16 bit MS-DOS Subsystem Error

hey, i got another problem!

just today each time i restart my pc, and get onto my desktop this error appears.

http://img139.imageshack.us/img139/3361/defragnr7.jpg

now i just hit close and nothing happens after that....but it would be interesting to know why this is happening, my hardware isnt full, its got 20gb left on it...so i dont know why it wants to defrag...

but yeah...im pretty much clueless as to why this has just started appearing today...

any help would be great, thanks for reading

This is often although not always a symptom of Spyware.

Try this approach first:

Read This First - IMPORTANT Instructions

Post a HijackThis log over in that section.

If they give you an all clear and the problem persists return to this thread and we can look further.