I am trying to troubleshoot a serial port problem and possibly a Bios failure.

When my PC tries to boot up I get a message that says: "Windows could not start because the following file is missing or corrupt:
\WINDOWS\SYSTEM32\CONFIG\SYSTEM

I'm guessing the Bios is all messed up. How do I correct it?

The Bios chip on my TX Pro II motherboard (shown here: http://www.amptron.com/html/pm9100d.html) is AMIBIOS DJ85531.

I'm kind of new at this so I really need some help

first repair windows. If bios was messing up, u shouldn't start. Maybe it's a problem about a driver not recognize by XP.

That file is needed to load windows, not your bios. The file is probably corrupted, or possibly screwed up by a virus. I agree with taxi... repair windows and things should get better.

How do I repair Windows if Windows won't boot? should I boot from the CD? make a boot floppy? or start in safe mode or something like that?

It's definately not the BIOS. It would complain when you boot and make many beeps. The fact you got that error in windows suggests all. If you want to reinstall(repair) windows, it depends on what version of Win you're running. A brief guide is as follows - Win 95a (CD version) can be reinstalled by downloading a bootdisk from bootdisk.com with cd support. Unpack the contents to a floppy (borrow someone elses computer if you really can't start windows, not even in safe mode). Plop the floppy in the drive before it boots Windows, then format the hard disk. This can go wrong if you're not careful so do a bit of research on the net first. Then reboot with the floppy in the drive and pop your win CD in. Type setup and have your numbers to hand.
Win98 is sooo much easier. Make a boot disk from the last tab in Add/Rem programs and use that to boot to DOS. Don't ask for CD support because you need to format the disk first. Then reboot and use CD support. Plop your CD in and type setup. It is much easier from there.