Weird problems with XP....

I've got a Dell Inspiron, running Windows XP and the latest Internet Explorer version.

The last few days weird things have been happening.....when I'm searching the internet the active window will freeze up until I hit Ctrl+Alt+Del and click that window, then click back into the original window. It has also been taking forever to shut down, sometimes it just freezes and won't shut down at all. It takes a while to get a program like IE or Word to open too. If I try to open Spyware Doctor, it won't open at all.

Any idea? Spysweeper and AVG haven't found anything.

 

It also acts like it's refreshing the screen in IE, even when I don't hit anything.

 

Anything? Anybody got ANY ideas? They don't even have to be good ones.