|"My only available solution to fix a registry coruption was to reinstall windows XP home dition"|
It wasn't the only solution...it was the solution you chose. You could have tried one the many registry repair fixes listed at Microsoft.com or simply performed a "repair installation"
If you indeed have a parallel install on the same partition, I suggest you go with XpUser4Real's suggestion(s)....backup your important files, wipe the HDD & start from scratch.
BTW, if you only have 256MB RAM, you should seriously consider an upgrade. 512MB should be considered the minimum...1GB (or more) would be better.