I was trying to burn a DVD whilst surfing the internet, when the computer froze. I switched it off via the switch on the tower unit, and expected it to reboot as it has in the past, but this time it froze on the black windows screen with the blue progress bar underneath.

On switching it off again I got to a black screen offering options from a normal boot to a boot in safe mode. The safe mode reboot worked, none of the other options did. After powering down normally the machine would not restart - the same problem as before.

I have tried system restore, and Norton System works 2003 "windoctor". Norton tells me there are no viruses. Superantispyware cleaned out a dozen or so malware items.

Sometimes the machine will boot normally, and work well, on other occasions it freezes at the screen described above.

The machine is about five years old; it came from PC World without a WinXP disc.

Any suggestions would be appreciated.

Try running Check Disk.

Go to start > Run...

cmd


From the command prompt, enter: chkdsk /r (note the space between chkdsk and /r)

You will be told the volume is in use do you want to run check disk on reboot?

Type Y and reboot.

Note this may take as much as a half hour to run on reboot. Just let it run.