For a couple of weeks, I tried to diagnos a no boot up problem I was having.
It would freeze at start up. Trying to figure what was going on I took many steps, tested memory, hard drive etc.. As it turns out, it will not boot if there is a USB plugged in on any of the ports. One morning, windows kept crashing, freezing and yelling obscenities at me. I slammed the lid shut, causing more destruction, not only did I break the screen, no biggie, use my TV as monitor anyhow, I had errors telling me files were missing, I took out the hard drive, hooked it up to my other PC, drive is readable, noticed system32 folder was missing 75% of the files. I was able to transfer important files, now I want to re-format. Well, ain't that a load of fun.
It refuses, I've tried XP home, XP PRO and vista. With vista it crashes and says couldn't import files or something like that. XP does a quick format but stays at 0% with the full format. After a quick format, it began to install, hung a couple of times, then those "unable to copy files" came spitting out like mad. I'm trying to boot from my external drive and it does not read the drive, all I get is a BOOTMGR is missing error, ER! You think??
My only guess is the hard drive, although it passed the drive test.