, a most reliable website for info on STOP errors (so called because they result in being unable to use the system):
One of the many processes or threads crucial to system operation has unexpectedly exited or been terminated. As a result, the system can no longer function. Specific causes are many
, and often best resolved by a careful history of the problem and the circumstances of the error message."http://support.microsoft.com/kb/841005
You have a hardware problem...at least one...and it's bad enough to result in the error messages and situations you describe. The F4 error message is the key one.
To try to troubleshoot such from afar on such an old system...is not something I will attempt.
The best advice I can give you is to take in to a reliable computer shop and have someone look at it...or move on to more recent equipment.
Someone else here may take a different approach.