If you had to do a system repair by putting your XP Windows CD in and after it is finished it didn't display any icons on your desktop and/or it won't allow you to reactivate windows you will have to do the following.
Reboot the system in safe mode (F8), go to the control panel - add/remove programs - uninstall Windows Internet Explorer 8 then reboot - activate windows and your icons and programs come back.
If you can't get into windows because you get stuck in the activation loop, you can't activate windows in safe mode so give it up and reboot to Windows Command Prompt. This brings you to DOS mode.
Do cd.. (enter) until you get to C:
At the C: type this in. Make sure it looks like this: C:\windows\ie8\spuninst\spuninst.exe then hit the enter key.
That should remove the ie8 or 9 from the system.
Now reboot in normal mode and do the activation. It will do the activation and your icons should reappear.
I don't know why but internet explorer 8 screws up the repair sometimes and it won't come back up until you remove it.