if only 1 hard drive shows in device manager then you do have 2 partitions on a 40gb drive, my suggestion is get one of those handy imaging software programs like archos or ghost, create an image of your system as is currently onto an external hd, then buy your larger drive, and load the image you created onto the new drive and whamo, you have a bigger drive, or you can always go ahead and use the factory restore disk and just have to re-install all your software loaded currently...