Windows XP automatic update ouch?

I will star with my comp. specs, I am using an ancient Compaq Presario 061
OS: Windows XP Pro SP3
sys mod: DM171A- ABA55000NX- NA310
Processor: x86 2486Mhz
physical memory: 286.00 mb
HDD:30.82 GB
RAM: 248 MB
Celeron CPU 2.5 Ghz

I hope that is all correct or makes sense. Anyway, I took automatic updates for my computer after defragmenting it, and when I came back to my computer a while later, It had rebooted to a blue screen error STOP 0x000000ED UNMOUNTABLE_BOOT_VOLUME, now all I can do to turn on my computer is plug/unplug the power cord a few times to get the same error. I have tried my install disc for windows and I get a "usbehci.sys is corrupt".

Upon the blue screen error it tells me that I have to push F8 for advanced options and disable BIOS memory but I have no idea how/when to do this.

so any help would be greatly appriciated I am a little lost at this point rolleyes