Hi twoyorkie,
The problem I had last week with my Toshiba A100, is not all that disimilar to yours. I had a complete disaster and I had no idea what to do. I new my hard drive and cpu were still ok, just the system itself was awry. From the best advice I got, from this forum and other tech people, the ony way to solve these kind of dilemna's is to do a total HDD recovery. But I must point out, that you DO NOT use any of the Windows based recovery media. First of all if you have the manufacturors supplied HDD recovery disk, this is how you must proceed. (If you don't have one, the computer company will supply one for you at a small fee, down here in OZ for example, if I didn't already have mine, Toshiba would supply one for about $15aus).
First of all you insert the disk into a CD drive whilst the computer is on. Then you shut down.
2/ While holding down the 'C' key, press the power button on a continue to hold the 'C' key until the recovery procedure begins. Let it run it's course. Note, on some systems it may be another key, it might be the zero numeric key and others use the 'R' key. This you'll find out from your HDD recovery instructions.
3/Once your recovery has finished, the computer will be back to it's original configuration. A word of warning! DO NOT use the Windows back utility prior to doing the HDD recovery. Instead, copy all your important documents, pictures etc. onto a CD or CD's and reinstall them later. Any software you might have installed after purchase, should be reinstalled from their origonal disks. If you downloaded any software, you'll have to do it again. (Sorry about that part, but it's the only sure way, it will also help you to discover what screwed your computer in the first place.)
I hope this well help, cheers.
Puddlejumper.