icon problem- not refresh at all.....

I have a problem of icon: they are not refreshing at all. No matter I start an application, pin it at anywhere, the icon are not shown. There are just white-sheet-with-a-square default icon for unknown file type. Even worse, the icon of recycle bin doesn't change when I put something into it or empty it until I press the F5 button......

Did I screw up the system some how?

I am running Windows 7 home premium x64.

Thanks all.

Hi dis2046

Have you disabled any services?

BTW, What is your system specs?
If you wish you can enter your specs in the UserCP, so you don't have to type them out on every post.