Shoween :
That seems like a quite probable issue, that the drive format isn't compatible with windows. How would I go about this? I installed Partition Wizard but am quite unsure of what to do, I'm quite worried that I might accidently do something that will erase the drive.
Partition Wizard is quite safe. You queue up a bunch of changes, and it doesn't actually make the changes until you click the big Apply button at the top. So it's very difficult to actually do something accidentally.
Reading up on other people trying to do the same thing you are brings up two important points, one good, one very bad:
http://forum.videohelp.com/threads/353769-Connecting-a-PVR-drive-to-a-PC
1) Good news. These DVD writers frequently use ext2 or FAT32 with the partition ID deliberately set to the incorrect value. That would explain why Windows can't see any partitions. If this is what's going on, it's a simple matter of changing the partition ID to the correct value. Partition Wizard can do this - right-click the partition, Modify -> Partition ID.
2) Bad news. These devices nearly always encrypt the video files they store. This was probably mandated by Hollywood before they were allowed to bring the product to market. The encryption keys are probably built into the DVD writer, so without the original device working and the drive inside it, you are unlikely to get any video files off of it.
DVD writers sold outside North America may not have encryption. And the initial batch of DVD writers which entered the market probably didn't have encryption. So it's still worth trying to get your video files off the drive. Just don't get your hopes up.