Windows doesn’t allows the user to delete or replace the protected system files that are very essential to run Windows smoothly. But we can’t follow Windows rule all the time since we need to experiment with various system files in order to change the functionality or the look of Windows.
In most of the causes Windows will not boot if you have not replaced the system file neatly or if you have tinkered with system file in an inappropriate way. To avoid all those frustrations we need to know the right steps to a replace a system file.
In Windows XP, we used to use a software called Replacer, but it’s not fully compatible with Windows 7 and Vista. Unlike Windows XP, Vista & 7 doesn’t require to disable “Windows File Protection” feature to play with system files. You can start playing with system files by taking ownership of the files in Vista & 7.
Follow the below steps to replace any system file with a new one or to modify it. Make sure you follow the instructions before start the adventure. For instance, let’s consider a system protected file labeled Shell32.dll as the file to be replaced in this guide.
* The best way to start the procedure is to backup Windows. I recommend cloning software like Macrium Reflect (Free) or Acronis True Image or Windows 7’s inbuilt image backup feature to create a good backup.
* Head to the folder where the file is located. In this case, Shell32.dll file can be found in “C:\Windows\System32“. Where “C” is your OS (Operating system) drive.
* You can simply create a backup of system file by renaming it. But Windows doesn’t allow you to rename a protected file. So, user needs to take Ownership of the file to rename it.
* Read my detailed “How to take ownership of a file in Windows 7” to take the ownership of the file (Same method applies to Vista as well). Once you have the ownership of the file, rename the file. For instance, rename Shell32.dll to Shell32OLD.dll. Simply click Continue button if you are prompted with security dialog box.
* Obviously, the next step is the copy a new file to with the same of the system file to the same folder. Fox example, you need to move/copy a new “Shell32.dll” “C:\Windows\System32” folder. Also note that it should be a valid file.
If you have replaced a system file with invalid file means Windows will not boot next time. So make sure that the system file is valid and works fine with the version of your Windows before replacing the file. You can also delete the file once you have the ownership of the system file.