"My Computer" system folder freezes

When I double-click "My Computer" on the desktop, the folder opens, but
almost all commands (change a setting, my network places, my documents,
control panel) cause the "My Computer" window to freeze, and I have to
terminate it. I have no problem accessing the various system folders etc
from the "start" button.

Any idea what is going on?

Thanks,

Clem.