Ernie, thanks for the compliments, I might understand MTU products quite well but to tell you how to restore your computer to it's original state is another thing

It depends on a number of factors, sometimes you are supplied with an original installation disc, sometimes the hard drive has a hidden partition with the original files, in which case there is normally a program listed in the Start/programs list named something like restore or recovery, I can't tell you exactly you would need to read up literature that came with your computer.
Other times your asked if you would like to make a recovery disc to free up more room on your hard drive, so if you did something like that when you first purchased your computer, unless you still have those disc's or the original installation disc I'm afraid your up the creek.
The only other option I can think of is to buy a new copy of Microsoft windows and that's not cheap.
So the first thing is to see if you have a recovery program listed.
If you have still got the original installation disc or backups you may have start a one time boot by turning on the computer then hit the F12
key just before the first screen appears to make it boot from the CD disc, if you don't catch it in time you will have to let it load as normal and shut down and try again.
It can be a long job reinstalling as if it is a few years old there can be a lot of Microsoft updates to install as well which has to be done over the Internet so I would make this a last resort.
What are your other problems you are having ?