Is there a why to stop lagging on youtube?

Well before i installed adobe and some other things (small things like updates), my computer was really fast on youtube and a browser game. Now on youtube the video plays sounds but the visual of the video slows down and kinda pauses from time to time. The browser game too, before was fast and responded fast, now it takes a while to chat respond and other things. Is there a way to make it faster, i already tried spyware and cleaning up the disc. So far nothing has helped. My compuer is a Windows XP.