Free driver downloads for Compaq Presario f700

Question

I recently had a friend clean/clear my laptop. It is a Compaq Presario f700/f767cl. It came with windows vista but he took it off and put windows xp on it. Now i think he said I need to download drivers for my sound to work. My screen looks wavy when i scroll up and down. So I think he said I need a video driver. I basically would like to download these to my laptop for free so I can get it working properly. I went to www.hp.com and dowloaded the drivers from there, but that did not work. So if you could please help me that would be great. THANKS.