Googled and found this:click here which might help.
Partition Improperly Dismounted
I poked carefully at the computer with various tools attempting at all costs not to alter any data written to the disk. Using Linux (Knoppix stand alone bootable CD) I was able to view the partition and see that all my data was just fine. I tried Partition Magic and it reported the error message "partition improperly dismounted". While Partition Magic is able to cure many problems with partitions it was unable to fix this problem by itself. Searching for that term on the net I discovered the cure.
The fix was to run check disk (CHKDSK) to fix the way the file system was laid out. Specifically, "CHKDSK /p" was the command. However, a plain CHKDSK revealed a single bad sector so I actually ran "CHKDSK /r" which will fix the sector problem as well as the partition problem. Executing this command properly set the flags for the partition and file system so that it could be mounted and booted from once again.
But, the system was dead so how to run CHKDSK? That turned out to be very easy. Just boot from the Windows XP install disk. It allows for a console from which many common tools including CHKDSK are available to run from the CD.
I was back up and running in fairly easy order. My time invested in the actual fix was probably 5 minutes. However the computer took an hour or so to carry out that fix using CHKDSK. But once it was done I could boot with no problems.