Computer Registry help

My computer has been lagging for the past month. I got a P4 2.4Ghz, 2GB DDR SDRAM, and a 128MB Radeon 9800. And its getting laggy when I’m just doing mundane stuff such as surfing the web. I scaned my computer using Ad-Aware and clearned out all my spy ware. And a friend of mine told me my registry is probably filled up or something like that. Is there any program out there that can help me clean out my registry? Thanks :thumb: