|I've seen this a lot in XP. It seems XP loses track of the partitioning information on some hard drives. I'm not sure if this only happens to a particular brand of drive, or if is just a random/unexpected hiccup that occurs. I had one drive (Western Digital, from memory) that used to "go raw" a couple times a year. I used some software (can't recall the name) that backed-up the partition table, and could be used to repair/replace the missing data/table.|
Some file recovery programs would probably have the capability to recover the FAT table. The problem isn't that you've lost files, just that Windows can't see the partition they are on, due to a loss of the FAT table (or maybe corruption of it).
Seeing as how you can access the drive in "Safe Mode", I'd definitely backup all data on the drive. Once everything's backed-up, use Windows Disk Management to format the drive.
Before using this drive to store any important files, I'd consider running the manufacturers diagnostics tools on it. From my experience, once a drive starts to exhibit faulty behavior, it's a good idea to replace it.
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