why did my hard disk delete everything

[Rex12]

Yesterday my computer froze and when I restarted I found it would not boot.
I tried everything to recover but it was no use...I finally managed to see that c drive showed empty as if it had been deleted.
I reinstalled windows and at this time it seems fine but is a pain updating drivers and re-installing all my software.
I was just wondering what could of caused this and if it is likely to happen again.
I ran a drive scan but found no errors or bad sectors
any ideas? thanks in advance for your input

 

[Solandri]

You're not going to like the answer.

Usually this is caused by the partition table becoming corrupted - that can happen if the computer freezes or loses power while it's writing to the drive (or if it's an external drive, you unplug it while it's being written to). The partition table tells the computer how the space on the drive is arranged and where the individual partitions are located. Each partition itself then lists the file names and where they are on the drive. If the partition table becomes corrupted, then the computer can't find the partitions, so it can't see any files, and it assumes the drive is empty.

Because the partition table is so important, there's actually a backup copy of it kept on the drive. You can use partition management software to copy the backup partition table over the (corrupted) main copy, and your drive will be back to normal with minimal fuss. The Ultimate Boot CD has a variety of disk partitioning and management tools which let you repair problems like this.

Even if both partition tables are lost, it's possible to manually reconstruct them on most drives, since they frequently have just one or two partitions. Knowing where the end of the partition is isn't very important, you just need to know where the partition starts. Since the actual partitions and the files are still on the drive, it's usually not that difficult to find the start of the partition(s) and reconstruct the partition table. You just have to assist the recovery software by telling it what kind of partition it is (usually NTFS).