Trick to bypass the xp if license is expired.

1. login the PC,
2. When ask for activate now, click on Yes
3. minize the Activation screen
4. Press windows Button + U, you found a Narretion screen.

5. click on Microsoft website. Here you  have success to open explorer.
6. open the systemroot(windows\system32\cmd.exe
7. Here you type a commnad, as below
8. For XP SP2 ( I am not cleared for SP3)
C:\windows\system 32\rundll32.exe syssetup,SetupOobeBnk

This will reset XP trial, and can be done 4 times (120 days).
If your xp was expired, and you've rearmed it, then you can rearm it 2 more times with this command.
(Delete the space between system and 32, in the command line)


9. For Vista / window 7
C:\windows\system32\slmgr -rearm

or

C:\windows\system32\cscript slmgr.vbs - rearm


It 100% work ...