or an older operating system?looks like you may have some hardware issues.download ultimate boot cd from this link.Follow the directs to burn the image to more...
HP Media Center m7250n PC Desktop - Troubleshooting
when you need the computer the most. I've run across this boot error message many times since Windows XP was released and luckily load the "fail-safe" default settings and reboot.
If neither of these issues are the cause for the Unmountable Boot Volume, then the issuemore...
HP Media Center m7250n PC Desktop - Troubleshooting