Hi Sorcha,

I don't pretend to know much about these glorified TV sets, but from my limited experience I would check out:

How much free space do you have on your HDD?
If the HDD is close to full, then defrag will come up with all manner of excuses not to finish or behave properly.

Are you using Win98 defrag? (This is the only OS I have any real experience of).
I personally found that using defrag from Norton System Works to be much better, also the extra tools provided help keep my system running smooth-ishly.

There are many far more experienced people around here who already have helped, and will help you.

Good luck,

John