i'm in alot of trouble. my computer is saying i have a missing or corrupt file <windowsroot>\system32ntoskrnl.exe.\
is this something i can fix myself. i don't have any of my original disks. i'm using a compaq presario desktop with windows xp
You need some type of OS disk to repair or re-install Windows. This just happened to my main PC just last week out of no-where. I booted to a repair screen, my whole Windows directory dissapeared. Not saying that's what is wrong with your computer, but you need a bootable OS disk to check on things.
You may also have a hard drive that is going bad, but either way, you need a Windows disk to either repair or re-install on your current drive, or on a new drive if you find that this one is bad. The BIOS may have a drive test option in it, or Compaq/HP may have a dowloadable utility to run to test your drive.