1.) Terminate any unnecessary programs.
2.) Unplug any unnecessary hardware, such as printers, scanners, etc.
3.) Make sure you run the scans...your antivirus, Ewido, etc.
4.) Corrupt or otherwise modified system files can cause the upgrade operation to fail and enter a continuous reboot cycle. If this is a retail version of XP perform a repair installation of Windows; If it is an OEM Recovery System then run a non-destructive recovery.
5.) Make sure your system has the latest updates from Windows Update.
6.) Click here to download a misc. update from Microsoft that fixes one such cause of this problem.
Once the above has been completed try installing SP2 again.
Hope this helps,
I have a Toshiba A-10, running Windows XP professional, service pack one. Have tried to upgrade my system to service pack two on three different occasions. The first time I used the updates download option. I also updated the bios prior to the first attempt. The updates downloaded completely and stated it installed and rebooted. It then went into a maddening reboot after reboot after reboot. I finally was able to get a Microsoft employee to help me restore it (after several hours).
I ordered a disc and tried it again. It did not change anything. The same behavior occurred and the same amount of time to fix it.
Since then I have been reluctant to try it again. I did several searches and followed the recommended installation instructions. The third time rendered the same results.
Any ideas? I have updated 3 Dells in my home without issue. Any ideas?