Boo,
sounds like you are running windows 98 or ME ??

try scandisk /f at the command promtt. THEN reboot. Once the scan completes, it should recover any lost sectors, and you should be OK.
This is your Internet Explorer browser dying - not too gracefully !!
It's possibly caused by a conflict with other software.
Did you change anything recently ?
Did ya apply any MS patches or service packs ?
Did you add any new programs/software or device drivers ?
IS this a first time error condition or has this been going on a while ?

Regards,
Steve