Hello louieee, you might have a corrupted file.
Maybe you should look at the Computer Virus and Spyware section and follow the instructions first.
Look
here(Look at that. These people have taught me everything I know. Thanks CH)
Do you have your Windows CD... you might have to do a reinstall of the O/S... but thats a long way down the track yet. (just handy to know where it is if you need it).