It should give this error when scanning through the directories, looking for invalid directories and files. This can go on for a REALLY long time. I once had a hard drive with *almost* all the pins into the IDE connector, and I completely trashed everything on the HD. I think I ended up putting a rock or something on the enter key just so I could leave the computer....
The number of folders it can find is way more than 512 (this is the limit for folders in the root directory). On my P-90 (812Mb of HD space) I already have 277 folders. You people with working windows use 'Find' and tell it to find only folders. When you search, it will return every folder on the C drive. You try to tell me it is less than 512!
This could take a while... I would suggest just formatting the HD if you don't have the time, and have a backup of it (before the failure).
JigPu