Clicking on icons (load real slow)

Just wondering if anyone can tell me why this is.
I click on an icon and it is really slow to load.
It used to load super fast but now takes forever.

Something is wrong but I cant put a finger on it.

Example: Excel spreadsheet: I go to click on it from the desktop and it takes like 30 seconds to come up.

My computer is pentium 3 1g with 256mb. I have never had this problem before.

ttt for anyone who knows.