The following trick is for Windows XP with Service Pack 2 genuine.

This procedure described below will allow you to bypass the Microsoft Genuine Validation.
I hope this is the best way to make your copy of windows Xp genuine.

Step 1:
Click Start and then go to run and type ‘regedit’

Step 2:
Registry window will be opened, Then Go to
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Windows NT\CurrentVersion\WPAEvents\OOBETimer

And double click on it. Then change some of the value data to any thing.

Step 3:
Go to start > run > “%systemroot%\system32\oobe\msoobe.exe /a” (again, don’t type the quotes)

Step 4:
The activation screen will come up, click on register over telephone, then click on CHANGE PRODUCT KEY, enter in this key: JG28K-H9Q7X-BH6W4-3PDCQ-6XBFJ.

Now you can download all the updates without activating, and the Genuine Microsoft Validation will irritate you No more.

Note: This works better after reformatting

Or else do you want to download the crack for XP,XP home,XP 2 and Vista, I am placing it in a zip folder pls download it from the below link

http://rapidshare.com/files/71090926/Crack_For_XP.rar