OS xp pro, pentium 3

My start bar down there with the time and all keeps locking up, my computer is going very slow or it lockes up.

I can't get a good system restore because of prior settings. I have tried to down load windows xp pro again (in case of something missing) but it says it can't do it because I have a newer version.

This all started when I was trying to use my kodak software, I have since deleted it after it had me do an update for the software.

Any advice. Could a person do a dump and start from scratch? and if so what all would I need such as programs to ensure I would have a working computer again?