Is your Computer full of Viruses or Spyware? Do you need to get back to work urgently without much trouble? You have no other option than formatting you PC and Reactivating the Operating System(Windows) again. But You can surely save your Reactivation time for Windows if you are using Windows Xp.
It is possible to Reactivate Windows Xp by just tweaking a single file from the System32 windows folder. When you install Windows on your computer for the First time, XP creates a file called “WPA.DBL” and saves it in the C:\WINDOWS\SYSTEM32 directory.
Now before Formatting your Computer just copy this file in any external storage device like a USB Flash Drive or an External hard drive. Then Format the Computer and reinstall Windows. While reinstalling Windows, you’ll reach the point where you have to activate. Decline the activation and complete the installation.
Now Restart your computer in Safe Mode by pressing F8 on Startup to get into the Advanced Boot Options menu.
Go to C:\Windows\System32 and you should see a file called WPA.DBL already there. Simply rename it to something else like WPA.BACKUP(or anything else) and then copy your backup version of WPA.DBL to the current location.
Now restart your Computer and your Windows will appear working fine. You have successfully activated your Windows Xp without much trouble. Remember that this will only work if you use the WPA.DBL file on the same computer that it 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. Basically, XP looks at the hardware of the computer to create a unique profile for just that one computer.