No System Restore on Windows XP

I re-placed a failing harddrive about 6 weeks ago. No problem or that's what I thought. Well I was just looking around the other day and went into system restore, well I didn't get into SR as I get an error message that says: System Restore has encountered a problem. Further information states it has to do with an error signature and then lists some really weird things like AppName, Offset, Modver, Modname, I didn't give you all the info as I am not sure what it means.. Did I lose something when I changed out harddrives and then transferred data from the old to the new HD Western Digital 160. Everything else works great, am I shafted or what. I really don't want to reinstall the original Windows OS XP disc as I would lose everything. Kinda of lost here in Arizona and would like some help. Have very little knowledge on these things.Sorry if I am not posting in the right place.