My year old HR24 was acting wierdly, locking up, turning it self on in the middle of the night etc. Booting up and using the SELECT key got me into menu for checking the system and Hard Drive, which indicated that the Hard Drive was bad. Instructions elsewhere here tell of putting a new Hard Drive in an HR24-100. HR24-500 is a little different. No screws on bottom, but the same two clips at back that need to be shimmed by 1/2 strip of plastic, like from a credit card. Then a small screw driver to lift the cover at one corner, and then the other opposite front corner, and then keep lifting till it all pops off. Inside the Hard Drive is inside a black rectangular plastic case with a fan at the end. The case is easily removed if you have a T-8 screwdriver, remove the 4 T-8 screws and the case and drive lifts up and off. 4 Phillips head screws hold the drive inside the case, and 2 more Phillips head screws hold a spring on the side to hold the drive off the floor of the unit. Removing all those screws its trivial to remove that data cable and the power cable, and put in a new drive. I chose a GREEN POWER Western Digital 1 TB AV-GP SATA 3GB/s Intellipower 64 MB Cache AV Hard Drive WD10EURS about $63 + shipping at Amazon. I've read anecdotal stories of larger capacity drives slowing down the unit too much as it fills up with recordings. I returned a piece of foam rubber that was on top of the drive in the case. The new drive was screwed in, and then the bracket was screwed into the chassis with its T-8 screws. The Top just popped back onto the case, and upon powering up, the Unit found the new drive, formatted it, and my system is good as new, with now more than double the recording capacity. The new drive is running at about the same 120 degres F that the old 500 Gig ran it, but quieter. No Service call required, no replacement by a pot luck receiver, no buying a new unit for $200 and no new 2 year commitment.