1.Goto "start"
2.Run-type in "regedit"
3.Goto "local-machine-software-microsoft-window s nt-current version-wpaevents"
4.choose "oobe timer" in the rights panel
5.in the window,delete all the things.
6.close regedit
7.goto start-run-type in "%systemroot%\system32\oobe\msoobe.exe /a"
8.choose the second option "use phone to activate"
9.click "change product key"
10.type in the serial:thmpv-77d6f-94376-8hgkg-vrdrq
11.click "update"
12.click"remember later"
13.after that restart the computer
14.after restart goto start-run-type in "%systemroot%\system32\oobe\msoobe.exe /a"
15.it should come up with a message"windows activated"-finished!

It was tested & it works 100 % Only For Windows XP.

Thanks.