I had $1000 on an encrypted wallet and need to restore it on bitcoin qt I reinstalled windows7, but luckily it saved my old windows in windows.old plus i backed up encrypted wallet to external device.  How exactly do I restore it?
Be very careful. First, shutdown Bitcoin-Qt completely. Rename its current wallet.dat file to something else (you can delete it, but just rename it to be safe). Then put your backup in its place. Start Bitcoin-Qt and you're done.