System startup problem

[hud]

After installing SP2, my computer will sometimes not start. Hard drive light is on but not the usual clicking. It is becoming more common now. Have to turn it off and back on again to get it to run, sometimes several times before it goes. I haven't installed any other new software or hardware. I run XP home, NAV, Zone Alarm and Spyware blaster. Not sure if this problem is related to SP2 or if I have a hardware issue.

Any suggestions would be greatly appreciated.

[pip22]

Microsoft have released a list of applications which may cause problems after SP2 is installed. Norton AntiVirus and ZoneAlarm
are in the list.

http://support.microsoft.com/default.aspx?kbid=842242.

[hud]

Thanks for the advice. Turns out the motherboard was in its last throes. Can't blame MS for that.