Hey bledd. I made a similar mistake a while ago. While formatting a new HDD I rather foolishly forgot to remove the Windows HDD. I went ahead and started a quick zero-fill of the drive since although it was "new" it was second-hand from a mate.
This particular utility on quick zero-fill basically trashes the first few MB of the HDD making it appear to be formatted. When I went to reboot my PC and saw lots of zeros I realised I did something rather silly
I used Partition Doctor [I think] and it managed to fix my MBR, MFT and the Partition Table.
Unfortunately the zero-fill nuked some Windows sys files too so I had to reformat my C partition and reinstall Windows. Before doing this though I slaved the drive on my mates PC and recovered my data with ease.
In the end I reformatted the whole drive and restored all the data from the backups. I could have carried on without reformatting everything, but I was getting some weird errors which I could only put down to the Partition Table not being quite right.
However, the new tables were good enough for me to recover my data
The lesson learned is to disconnect ALL drives except the one you are working on and to ALWAYS double-check the drive name you are working on. Maxtor 6Y819923 vs STQ276772782. If I had taken just 2 seconds to check before wacking enter
SiriusB