Win explorer stops responding

When I right click on an item in MyComputer window explorer stops responding then will restart explorer after I attempt to close the window or use Task Manager to end process.

This only happens in the top level windows, and not on the desktop icons.

Any suggestions.

Win XP Home SP2 Celeron 2.4 512 DDR333, SIS video, most current BIOS from manuf. problem was present with older BIOS.