Change or Spoof a MAC Address in Windows or OS X

Every NIC (Network Interface Card) has a unique MAC address (Media Access Control). This applies to all types of network cards, including Ethernet cards and WiFi cards. The MAC Address is a six-byte number or 12-digit hexadecimal number that is used to uniquely identify a host on a network.

An example of a MAC address is 1F-2E-3D-4C-5B-6A and it falls into the Layer 2 networking protocol of the OSI model. In today’s networks, ARP, or Address Resolution Protocol converts a MAC address to a Layer 3 protocol address, such as an IP address. A MAC address can also be called a Physical Address. Read my post on how to find your MAC address if you don’t know it.

mac address

All MAC addresses are hard-coded into a network card and can never be changed. However, you can change or spoof the MAC address in the operating system itself using a few simple tricks.

So why would you want to change your MAC address? Well there are many reasons for this, mostly related to bypassing some kind of MAC address filter set on a modem, router or firewall. Changing the MAC Address can help you bypass certain network restrictions by emulating an unrestricted MAC Address or by spoofing a MAC address that is already authorized.

For example, a WiFi network may allow only authorized computers to connect to the network and filters out computers based on the MAC address. If you can sniff out a legitimate MAC address, you can then spoof your MAC address and gain access to the WiFi network.

Another example is if you have an ISP that allows only a certain number of computers to connect to the Internet from your home. If you have more computers that need to connect, you can spoof the MAC address of an authorized computer and connect from a different computer.

Change Windows MAC Address

You can change the MAC address for the network card in Windows pretty easily following the steps below.

Step 1: Click on Start, then Control Panel, then Network Connections, and right-click on the network connection you want to change the MAC address for and select Properties. It will normally either be Local Area Connection or Wireless Network Connection.

local area connection

If you are using Windows Vista, Windows 7 or higher, you have to go to Control Panel, then Network and Internet, then Network and Sharing Center, and then click on Manage Network Connections or Change adapter settings.

change adpater settings

Then you can right-click on the adapter and choose Properties.

Step 2: On the General or Networking tab, click the Configure button.

configure network adapter

Step 3: Now click on the Advanced tab and click on the Locally Administered Address property or the Network Address property.

locally administered address

By default, the Not Present value is selected. Go ahead and click on the Value radio button and enter in a new MAC address. The MAC address is a combination of 6 pairs of numbers and characters, i.e. 40-A2-D9-82-9F-F2. You should enter the MAC address without the dashes.

mac address change

You can go to the command prompt and type in IPCONFIG /ALL to check that the MAC address has been changed. Go ahead and restart the computer in order for the changes to take effect.

This is the simplest way to change your MAC address in Windows. You can also do so via the registry, but it’s much more technical and probably not required by most people.

Change OS X MAC Address

Changing the MAC address on OS X is definitely not as easy as it is on Windows. Firstly, you have to use Terminal (similar to command prompt in Windows) to actually change the MAC address.

Secondly, you need to manually figure out the technical name of the adapter before you can change the settings. I’ll explain everything below step by step, but it gets a bit complicated at times.

To start, let’s find out the current MAC address for your Mac. You can do this in one of two ways: via System Preferences or via Terminal. Open System Preferences, click on Network and then click on the Advanced button. Make sure to select the appropriate interface first (WiFi, Ethernet, etc) in the listbox on the left.

os x network advanced

Click on the Hardware tab and you will see the first line is MAC Address. I thought you could simply choose Manually from the Configure dropdown, but that doesn’t allow you to edit the MAC address.

network hardware mac

In Terminal, you can get the MAC address by typing in the following command:

ifconfig en0 | grep ether

This will give you the MAC address for the en0 interface. Depending on how many interfaces you have on your computer, you might need to run this command several times adding 1 to the number each time. For example, I ran the following commands below until I reached an interface that didn’t exist.

terminal os x ifconfig

Now you can simply compare the MAC addresses listed here with the one you saw via System Preferences. In my case, my WiFi MAC address of f8:1e:df:d8:9d:8a matches with en1, so that is the interface I have to use for the next commands.

Before we change the MAC address, you can use a useful command in Terminal to generate a random MAC address if you need one.

openssl rand -hex 6 | sed ‘s/(..)/1:/g; s/.$//’

Now that you have a new MAC address, you can change the current one using the following command below. Replace XX with the actual MAC address you want to use.

sudo ifconfig en0 ether xx:xx:xx:xx:xx:xx

In order to do this, you need to be logged in as an Administrator or you have to enable the root account in OS X. By default, root is disabled and it’s better to leave it disabled if you can. Just login as an admin and you should be able to run the command just fine. It will ask you for your password, though, before changing the MAC address.

Also, the address won’t change if you are still connected to a WiFi network. You need to first disconnect from any networks and then run the command. Surprisingly, disconnecting from a wireless network in OS X is not intuitive at all. You have to press and hold the Option key and then click on the WiFi icon to see the disconnect option.

disconnect from wifi os x

So here is a rundown of all the commands I ran in order to get the current MAC address, generate a random one, update the MAC address and then verify to make sure it had actually changed.

mac address change os x

As I mentioned earlier, this is definitely not as straightforward as the process is on Windows, but you should be able to do it if you simply copy and paste the commands above. If you have any questions, feel free to post a comment. Enjoy!

The post Change or Spoof a MAC Address in Windows or OS X appeared first on Online Tech Tips.

How to Turn On Auto-Complete in the Command Prompt

Do you use the command prompt on a daily basis? If so, I recently found a way to turn on auto-complete for the command prompt via a simple registry edit. When typing in long path names, simply type in the first few letters and then press TAB to autocomplete either folder or file names.

For example, if I am typing in C:Documents and Settings, I would just need to type in C:Doc and then press the TAB key.

enable auto complete command prompt

dos prompt auto complete

As you can see, there is only one folder that starts with “doc“, so it automatically gets completed with quotes added. Now that’s pretty neat. If you want to continue further, just add another to the end and then press TAB. Note that you can add the forward slash after the quote and it will still work just fine.

You can continue through the different folders and files in a directory by simply pressing the TAB key. So if you type in C: and then keep pressing the tab key, you will be able to cycle through all the folders and files in that path in alphabetical order, i.e. C:Documents and Settings, C:Program Files, etc.

Note that this really only applies to Windows XP. In Windows 7 and higher, autocomplete will work automatically when you press the TAB key.

Enable Autocomplete for Command Prompt

Step 1: Click on Start, then Run and type in regedit in Windows XP. In Windows 7 and higher, just clicking on Start and then type regedit.

regedit

Step 2: Navigate to one of the following registry keys:

HKEY_LOCAL_MACHINESOFTWAREMicrosoftCommand Processor

HKEY_CURRENT_USERSOFTWAREMicrosoftCommand Processor

So which one do you pick? Well, here’s how it works. The Local Machine key will apply to all users on the computer, but will be overridden by the Current User key if the value is different. For example, if autocomplete is disabled at the HKLM key, but enabled on the HKCU key, then it will be enabled. You can tell if autocomplete is disabled when pressing the TAB key simply inserts a TAB space.

You can change the settings in both locations if you like, but it is really only needed in the HKCU key for autocomplete to be enabled.

Step 3: Double-click on the CompletionChar key and change the value to 9 in decimal format. CompletionChar enables folder name completion.

command processor

You can also enable file name completion by changing the value of PathCompletionChar to 9 also. Note that the value 9 or 0x9 in hexadecimal is to use the TAB control character for autocomplete. You can also use other keys if you like.

For example, you can use 0x4 for CTRL + D and 0x6 for CTRL + F. I personally find the TAB key to be the most intuitive key, but you have other options if you need.

You can also use the same control character for both file and folder completion if you like. In this case, autocomplete will show you all matching files and folders for the given path.

As mentioned earlier, the default value in Windows 7, Windows 8 and higher is 0x40 (64 in decimal) in the HKLM key. It should be set to 0x9 (9 in decimal) in the HKCU key by default, which means it will be enabled. If not, you can manually go and change it.

Overall, this is a great time saver for anyone who has to type a lot of DOS commands. If you have any questions, feel free to post a comment. Enjoy!

The post How to Turn On Auto-Complete in the Command Prompt appeared first on Online Tech Tips.

How to Uninstall and Reinstall Windows Updates

Even though installing updates in Windows is an easy process, the mechanism in the background that manages it all is fairly complicated. There is also a lot of misinformation on the Internet about how to deal with problems relating to Windows Update.

One of the biggest misconceptions is that all Windows updates can be installed at once by simply deleting the SoftwareDistribution folder stored in C:Windows. This is completely wrong. Yes, you might save some space (anywhere from 500 MB to several GB’s), but deleting the folder will not remove any installed update.

In addition it’s a bad idea to delete the SoftwareDistribution folder unless it is absolutely required. There is a subfolder called DataStore that has a large database of all the Windows Updates available. This database will probably be a couple of hundred MBs in size. Deleting this database simply removes the Windows Update history for the computer.

To prove this to myself, I did a test. I opened Control Panel, clicked on Windows Update and then clicked on View Update History in the left hand menu.

review update history

This screen just gives you a full list of installed updates with the Status, Importance and Date Installed. When we delete the SoftwareDistribution folder, this dialog will be completely empty as if you have never installed any updates. Before I show you that, click on the Installed Updates link at the top where it tells you how to remove an update.

windows update history

As you can see, I have a couple of hundreds updates currently installed for Office, Windows, Silverlight, etc. Now if you follow the instructions below for deleting the folder, you can go back to View Update History dialog and you will see it’s now empty.

blank update history

However, if you click on Installed Updates again, you will see that all the updates that were listed before and still listed there. This is because we simply deleted the log history of the updates and not the actual updates.

This dialog is where you can actually uninstall an update, but only one at a time. Simply click on an update and then click Uninstall. Unfortunately, there is no way to remove all updates at once unless you use System Restore.

uninstall an update

If you use System Restore and restore the computer to a previous restore point, any updates that were installed after that restore point will be gone. To remove all updates, though, you would need a restore point created right after the OS was installed. Even if a restore point was created at that point, older ones normally get deleted over time to make space for newer restore points.

Still, if you have a lot of space allocated to System Restore, you might be able to roll back a couple months worth of updates at once.

Once you delete the contents of the folder, you will need to revisit Windows Update via Control Panel and check for updates. The entire database will be built from scratch and you may notice that Windows shows Checking for updates for a very long time. This is because a list of every update applicable to the OS has to be downloaded again and then compared to the updates currently installed on the system.

Delete SoftwareDistribution Folder

In order to remove this folder, you first have to stop the Windows Update and BITS services in Windows. To do this, click on Start and type in services.msc into the search box.

services msc

Next, right-click on the Windows Update service and click on Stop. Do the same thing for the Background Intelligent Transfer Service (BITS) service too.

stop windows update service

Now navigate to the following folder shown below and you will see several folders listed there. The main ones that we will talk about are Downloads and DataStore.

C:WindowsSoftwareDistribution

software distribution folder

If you are trying to regain hard drive space only, then you should only delete the contents of the Download folder, though in theory this should not really be necessary. The Download folder actually holds all the updates that have been downloaded, but not yet installed. Once they are installed, the updates are removed within 10 days. So theoretically, that folder should shrink in size soon after you have installed all the Windows updates.

The DataStore folder contains the database with the full Windows update history for the computer. Once it is deleted, the update history dialog will be blank like I had shown above, but all your updates will still remain. You should really never delete the DataStore folder unless you are told to do so or if Windows Update is completely corrupt and misconfigured.

Note that you may not be able to delete certain folders and the ReportingEvents file. In the case where you can’t delete a folder, just open the folder and delete all the contents inside. For me, I got an error when trying to delete the DataStore folder, so I just went inside the folder and deleted the database file and all the other files in the folder.

Check for Windows Updates

If you did remove the SoftwareDistribution folder, you will want to go to Windows Update again to check for updates. It will show that you have never perform a check for updates since the update history is now gone.

check for updates

Click the Check for updates button and be prepared to wait a while as the database is being recreated.

Conclusion

So the main point here is that you cannot really get rid of all Windows Updates at once unless you have a really old restore point saved on the system. Secondly, you should only delete the Downloads folder in the SoftwareDistribution folder if you are looking to save space or simply install all the latest updates and wait 10 days to see if they are removed automatically.

Thirdly, you should only delete the DataStore folder if something is really wrong with Windows Update like not showing any new updates for several months, etc. Hopefully, this gives you a better understanding of how Windows Update works and how the files are stored. If you have any questions, post a comment. Enjoy!

The post How to Uninstall and Reinstall Windows Updates appeared first on Online Tech Tips.

How to Avoid Problems Activating Windows After a Clean Install

If you are planning on doing a clean install of Windows on your PC, you will more than likely have to reactivate Windows, either online or over the phone. Normally, the online reactivation will work just fine as long as the hardware on your computer hasn’t changed very much since the OS was originally installed and the version of Windows is exactly the same as the version that shipped with the computer.

If you have swapped out hard drives, graphics cards, memory, etc over time, then you might run into problems when you try to reactivate Windows online using the same product key. In these cases, you will have to call Microsoft and do an over the phone activation.

If the hardware hasn’t changed too much, you can make a backup of the information that Windows uses to ensure your copy is valid and then restore it after the reinstall, which I explain below using a freeware program.

Download Recovery Media

If the computer came installed with an OEM version of Windows and you perform a clean install with a retail version of Windows, it also won’t activate online. Previously, new PCs came with an OEM DVD that allowed you to reinstall Windows, but in the last few years most PCs now have a separate recovery partition that lets you restore directly from the hard drive. You shouldn’t have any problem activating Windows if you restore this way.

If you don’t have the DVD or recovery drive, you can either call Microsoft and try to activate by phone or you can directly download the ISO image files from Microsoft, but you will definitely need to have the product key from the COA sticker on the computer.

In order to download Windows 7 recovery media,  you have to enter a valid product key before it will let you download the ISO file. For Windows 8.1, you are not required to provide a product key for the download. You can get the Windows 8.1 ISO from the Create Media Reset page on Microsoft’s website.

It’s worth noting that for years you could download Windows 7 ISO images from DigitalRiver, an official distributor of Microsoft software. However, those have all been taken down and no longer work. Your only legal sources are the links above from Microsoft.

Another item to note is that if your computer has Windows 8, the key won’t be able to activate Windows 8.1. The same is true if you have a Windows 8.1 key and are trying to activate Windows 8. If you need a Windows 8 ISO image, then check out the Upgrade Windows with product key only page. Here you enter your product key and it will download the correct ISO image that can be activated for that specific key.

Windows XP

In Windows XP, you can avoid having to reactivate by simply copying a file from your Windows directory and saving it external media. When Windows XP is first activated, it creates a file called WPA.DBL and stores it in the C:WindowsSystem32 directory.

wpa dbl

Copy this file to your external storage device and keep it handy. When you go to reinstall Windows, you’ll reach the point where you have to activate. Decline the activation and complete the installation.

Now you’ll need to restart your computer in Safe Mode by pressing F8 on startup to get into the Advanced Boot Options menu.

advanced boot options windows

Go to C:WindowsSystem32 and you should see a file called WPA.DBL already there. Simply rename it to something like WPA.OLD and then copy your backup version of WPA.DBL to the current location.

Restart the computer and Windows XP should now be activated and working normally. Remember that this will only work if you use the WPA.DBL file from the same computer that Windows XP was originally activated on. If you install XP on a different machine and try to copy the WPA.DBL file there, it won’t activate.

Windows Vista, 7, 8

If you are running Windows Vista, 7 or higher, you won’t be able to simply copy one file in order to avoid the activation problem. There is a lot more information that is required, which makes it a lot more complicated.

Luckily, there is a freeware program called Advanced Tokens Manager that will make a copy of all the activation data for you and allow you to easily restore it later on.

Once you download it and unzip the files, go ahead and run the executable file. It doesn’t require any installation, so that’s nice. On the main screen, it will start detecting any valid Windows and Office products.

advanced tokens manager

If all works out well, the status should detect your version of Windows and it should display the product key along with the license status. To backup the data, just click the Activation Backup button. A fairly large dialog will pop up that basically explains all the features and the requirements in order for the activation to properly work. Make sure you read it carefully.

restore activation windows

The main points here are what I had already mentioned above: don’t make major hardware changes when performing the restore and make sure the OS edition is the same. Go ahead and click Yes and the backup will be created in a new folder called Windows Activation Backup, located in the same folder as the EXE file.

windows activation backup

You’ll want to make sure to copy this folder to some external media before you reinstall Windows. Once you have loaded Windows, simply download and run the program again. Make sure to copy the backup folder into the same folder as the EXE file. The program will detect the backup folder and the button will change to Activation Restore.

activation restore

Click on that and when it asks you if you are sure, click Yes. Wait about a minute or so and if the program succeeds, you will get a Success message.

activation success

At this point, you should be good to go with an activated copy of Windows. Note that if you Microsoft Office installed also, you can click the Office Activation Backup button and it will allow you to back that data up separately.

office activation backup

The only issue with Advanced Tokens Manager is that it does not fully support Windows 8.1. It can save all the activation data, but it can only restore activation for Windows 8.1 copies that were activated by phone. If activated online, it won’t be able to restore properly.

The developers say they are in the process of trying to figure this out, but there has been no update to the program September 2013, so that’s not a good sign. Either way, it works well for Windows Vista, Windows 7 and Windows 8. If you have any questions, post a comment. Enjoy!

The post How to Avoid Problems Activating Windows After a Clean Install appeared first on Online Tech Tips.