The stock harddrive is an 80 gig SATA and it just wasn't big enough for my needs. Ok, actually it was fine... I just like taking things apart and tweaking them! The specs claim you can record up to 60 hours of Standard Definition programming. However, I maxed the harddrive and was only able to hit about 42 hours of record time. The shows were a pretty even mix of 30min, 60min and 120min recordings.
Step 1: Items you'll need.
-A rotary tool (Dremel tm) with a grinder bit
-3 PC harddrive mounting screws (optional)
-A bigger SATA style harddrive (approx 160 gig recommended)
A quick note about the harddrive: I have read that you should only put 160 gigs worth of drive space in this box because it can only use that much - anything bigger is a waist of money and unused drive space. However, I bought a 250 gig drive because it was cheaper than smaller drives I was looking at and it works fine. At 99% full my new drive is holding 100 hours of recordings. Remember that that the original 80 gig could only hold 42 hours. The drive is 3 times bigger but is obviously not able to hold 3 times the amount of recordings. So the 160 gig rule seems to hold true.