Might just borrow this thread for a question..
I had around 2BTC on my computer 3 days ago. The computer had some problems and I had to reinstall the OS. Now, when i installed Bitcoin again, i got a new wallet, am i right? So the old bitcoins just.... dissapeared?
Just restore your wallet.dat backup.
Problem is, i didn't have time to take any backups, (except for stuff on my other harddrives..)
You just lost your BTC forever, then.
If the hard drive was not formatted but just had the OS installed, the wallet.dat file is probably on there somewhere. Do a search or look in \Windows.old\Users\(Your old user name)\AppData\Roaming\Bitcoin if using a recent version of windows. XP calls the old users folder something else. For other OSes just do a search.
Tip me at 16wEsax3GGvJmjiXCMQUWeHdgyDG5DXa2W if that helps. A minute ago you had zero right?