Compare the content of two files
You can use Powershell to compare two items. These items can be two text files or, in this case, to registry files to see what has been changed. First make an export of the registry to file1.reg. Then make the change and export the registry to file2.reg. To compare those two files use the following command.
Compare-object $(Get-Content ‘file1.reg’) $(Get-Content ‘file2.reg’)
The Compare-Object does the matching. Remember that the code in between ( ) is executed first.
Be careful when using this command for it can be very memory consuming when comparing two complete registry files of a computer. Do not start this on a productive server without testing on a separate workstation!