Windows wont start???

[Chopperhead]

Ok well this is for a computer at school. anyway I was cleaning out and dfragging the computer and all that and when I was done the windows update feature poped up so we said yes to download it left it overnight and when we whent to install it today everything froze and now the computer gets to the were it says welcome on the windows loading thing and it freezes.
the computer has win XP not sure if it's sp1 or 2
I cannot acceses the computer at all like I can not get into windows or anything. Plz help.
If you need any more info just let me know and I try and answer as best I can as this is not my computer and I dont know much about it.

 

[Speedo]

When it's starting up press F8 to get the boot menu. There should be an option "Use last known good configuration." Give that a try. If it doesn't work use F8 again and boot into safe mode, then take a look in the event viewer (Start>Run; enter eventvwr.msc) and see what errors it's showing.

 

[Chopperhead]

ok when do I push F8?? as soon as you turn the power on or.... at the windows loading screen or.... at that black screen that says your computer specs.....???

thanks.

 

[cidknee]

keep pushing it as soon as you turn it on, no jk, usually at the black bios boot screen