Update - now chkdsk does not work

I just updated all Windows XP Professional files using Microsoft update. I
have made no other changes with my system. Yesterday, I could run chkdsk (on
reboot), now chkdsk does not work. When rebooting, Windows simply ignors
this request even if check and fix disk errors is selected. What could be
the problem and solution here?

When I go through "Administrative Tools" to chkdsk, on reboot I get the
message "cannot open volume for direct access."

"TJD" <> wrote in message
news:QOJNf.1976$Uc2.250@fed1read04...
>I just updated all Windows XP Professional files using Microsoft update. I
>have made no other changes with my system. Yesterday, I could run chkdsk
>(on reboot), now chkdsk does not work. When rebooting, Windows simply
>ignors this request even if check and fix disk errors is selected. What
>could be the problem and solution here?
>