Hi! My PC is an old HP Compaq D530 CMT made circa 2006, 1GB RAM. I do know it's perfect just for XP, but I've been using it with Win7 and accepting the speed penalty. But lately it's getting slower and slower, Chrome or Firefox take 1 or 2 minutes to open a .HTM saved in local HD! Worst: I can no longer install any new program. Avast! Internet Security says it's clean. CCleaner made it even slower after "cleaning" the registry... I am about to format and reinstall it. The install disk has all choices, from Home to Ultimate. Will I get a smoother operation by choosing a lower category? Or uninstalling unneeded services? I do not run any games or hi-speed connections, just Office, web browsing and simple engineering software. Thank you!