Some time ago, I beleived that the frequent 'lock-ups' that I was having were possibly caused by a corrupt hard drive (already non standard at 60GB). I took it out and went down to my local friendly computer shop (the drive is just a basic 2 1/2" laptop drive anyway) and asked them to format it.
They did manage to format it eventually, as I asked - 'as if it were new'. After replacing in the machine and trying to initialise it failed due to 'disc has problems' message.
My suggestion is not to format it via a computer.
I gave up on this and bought another drive (80GB Fujitsu) which was recognised and booted up fine, but the machine has still locked up frequently when accessing the prog. guide or recording list. I am crossing my fingers the the latest software downloaded over the weekend helps.
According to other threads the OS in the Pace can handle up to 120GB