How can I fix my friend's HP Recovery (D:) drive?

Hi. As with the first reply do not alter or touch the D:Drive. This is the computers Recovery Partition and comes with almost all HP-Compaq PCs. On this drive is stored a full copy of the software and drivers including Vista and is used when your pc has trouble or you want to return to factory settings (the way it was when it was first purchased). Its like having a DVD/CD of Vista and all then drivers for the computer but on the hard drive. All of the files on this drive as hidden so you can't see them. In effect the D:Drive is a drive is not a usable drive, its a storage area for operating system, software and drivers for the pc. Hope this helps

The D: drive is a non-Windows partition. The reason you can't see any of the files is because it is in a file system that Windows can not read. The D: drive exists specifically for rebuilding the system back to the way it was when it was purchased. It probably also contains additional diagnostic software. Therefore, if you never want to restore the system to defaults or run diags, you could just delete the partition. However, I would recommend leaving it alone because when you finally decide you don't want it and delete it, you'll find that you DO need it and will be stuck. Edit: Almost forgot: The partition is out of space by design. Since this partition is a system partition that is only used for restoring/repairing the computer, there is no reason to give it more room than is needed for the files that are stored there. Any additional empty space would take away usable space from C: and just waste the space since it would never be used by the D: partition.