CHKDSK just keeps running! HELP

I ran chkdsk from the error checking utility, checking the two options, the computer restarted and ran chkdsk (the system is NTFS) it says "THE VOLUME IS DIRTY", chkdsk runs the 5 stages ok then the computer tries to reboot (normal startup screen) however then re-starts CHKDSK this has run approx 20 times taking 1 hour + each time. I can not stop this cycle, any one else seen this problem ANY HELP WOULD BE APPREICIATED.