HALP!!!!!!!!!

I saved over an image! I meant to click 'save as', but I clicked 'save'! I don't have a back-up. undo doesn't go back far enough.

Can you help me get it back? Can I set my computer to how it was half an hour ago? I know my sister used to do that a lot.

Please help. It was in ArcSoft PhotoStudio if that helps.

ARGH! *runs 'round setting hair on fire*