If the machine will boot, click Start, then Run, type chkdsk /r and press "Enter". You'll be told the drive is busy and asked if you want to run this on the next boot...type Y and press "Enter". Type exit and press "Enter". Reboot. This should run a full chkdsk operation on the next boot...this is a long check...let it finish. The machine should then boot to Windows normally.
Can't recall if it was a blue screen but I am doubtful will wait for it to happen again, willalso run chdisk/r today and let you know of results, just wondering if this is tied in with my other problem with Microsoft Outlook described on other thread.