find your walled.dat file and find a guide on how to backup and restore your wallet from backups. those will help you more than I can.
My wallet.dat is on several flash media devices, encrypted. Soon it will be in several locations separated by hundreds and in one case thousands of kilometers.
Another thing to back up, either with hints or writing it down and locking the written copy in a safe, is the password for your wallet. If you forget that, you're boned.