XP slowdown

[olopbob]

My XP has slowed to a crawl. Drop-downs don't respond, programs load slow and pages on net act like I'm on a 28K modem. I've checked my cable connection (it's cranking at 20X dial-up) my processor (AMD running over pentium 4 benchmark). Could the OS be my problem, what do I need to check? I tried the repair option on my connection and got a message saying it could not purge the DNS resolver cache (which I don't understand) but I don't know if that is the problem. If anyone knows any fixes or diagnostics I can run it would be helpful, or if I can do something to get my OS to run right it would be appreciated.

Thanks, Olopbob (Heavy user, poor fixer)