Go into Control Panel>Administrative Tools>Services and scroll through to the Volume Shadow Copy entry. Is it set to Automatic and is it running?
If it is, you might have a good chance of recovering the files using Recuva or similar. Recuva is free from http://www.pirirform.com, the CCleaner people.
If that Service is disabled, there's little chance of recovery. Just don't waste money on the scum who raied your machine - they have no reason to give you a decryption key once they've been paid.