1) You'll need VolumeID of course, first off, open google and search for "VolumeID download" It should be the first one that says "VolumeID - TechNet - Microsoft"
2) Once at this page, click on 'Download VolumeID (194 KB)' and save the file if it asks.
3) Put the freshly downloaded file onto your desktop, right click it and press "Extract Here" (assuming you use Winrar)
4) Now, locate to C:\ (or which ever is your main used.) and drag and drop VolumeID.exe and VolumeID64.exe there.
5) Now run Command Prompt (CMD) as administrator.
6) Once you open up Command Prompt as administrator, type in "cd C:" without quotes, and also if you moved it to some other place to cd Thatlocation, such as cd C:\System32
7) Now type in "Volumeid.exe 1234-5678 (Note, the numbers I chose are random, you can always replace them with any numbers here, as longs as it's 8 numbers max and you include the hyphen. Also if your Windows is x64 then type in Volumeid64.exe 1234-5678)
8) Press the enter key and restart your computer | If you get any errors, reply here with your error. Also, I don't remember, but VolumeID might be a false positive depending on your antivirus, I promise you it's not, it's a Microsoft made program.