my computer keeps booting on and on. No desktop appears. I can't use safe mode.I press safe mode and then it reboots again. I press> start windows normally and it again boots. I had changed the motherboard battery and had cleared cmos. but still it keeps rebooting. thanks for any help.

Resources for Troubleshooting Startup Problems in Windows XP

XP Logon Screen Does not Appear and the Computer Continuously Restarts http://support.microsoft.com/default.aspx?scid=kb;en-us;310396 http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q310/3/96.asp&NoWebContent=1 Black Startup Screen Is Briefly Displayed, Computer Restarts Repeatedly http://support.microsoft.com/default.aspx?scid=kb;en-us;314466&Product=winxp Access the Recovery Console and extract a new copy of the Kernel32.dll file from the original WinXP CD 1. Start recovery console as described above 2. Insert the WinXP CD 3. At the command prompt, type CD system32, press ENTER 4. Type ren kernel32.dll kernel32.old, press ENTER 5. Type map, press ENTER 6. Go to the drive that contains your CD 7. Type expand drive\i386\kernel32.dl_, press ENTER; Kernel32.dll should be listed as 1 file expanded 8. Type exit, the computer restarts 9. Remove the WinXP CD ========================================== The Computer Continuously Restarts http://www.kellys-korner-xp.com/win_xp_restart.htm Black Startup Screen Is Briefly Displayed, Computer Restarts Repeatedly http://support.microsoft.com/default.aspx?scid=kb;en-us;314466&Product=winxp Windows XP Restarts When You Try to Shut Down Your Computer http://support.microsoft.com/default.aspx?scid=kb;en-us;311806 ================================== Auto Reboot On System Crash http://www.theeldergeek.com/auto_reboot_on_system_crash.htm By default, when the Windows XP operating system crashes an automatic reboot of the system occurs. While this behavior can be convenient, the downside is the error message accompanying the crash is not visible. Often times this information can be a great help in troubleshooting the source of the crash. This behavior can be modified in two ways; via the registry or using the System Properties property sheet.

If you have not made any hardware changes........... and If you have another power supply laying around and if you are comfortable swapping out power supplys. do that real quick and see if it boots.

Problem resolved. I had a virus on the boot of the hard drive. Also at my McAfee antivirus it said about a new virus advisory of a high risk worm. This is what it says: W32/ircbot.worm!ms05-039 is a high risk worm. You can be infected simply by going online. Once infected, your system amy restart continously. So I had another hard drive wish I formatted and installed Windows xp. At my Amibios setup, I had Trend ChipAway virus enable on my western digital hard drive. So I used my western digital Data Lifeguard tools disk. Suddenly a message said that i was infected with the above virus.It said Trend Chipaway had detected a virus on the boot drive. And to go to certain website( i forgot) to remove it. I wonder where i can go to remove it.Thanks to all.