Ideally you will restore the wallets to the same place. However, MultiBit also includes a feature File>Open Wallet, that allows you to open and use a .wallet file on an arbitrary location.
In addition, you can make a backup into a multibit .key file using Tools>Export private keys. Once for each wallet, password-protection is possible. This can go into a bank vault on storage media as necessary. You can then re-import these keys, after reinstalling, into blank wallets if something should go wrong.
Thanks for the reply Hexa, much appreciated.
What would you recommend i do to safely have a back-up ?
As i stated in my first post PLUS export of private keys ?? Do i need to export private keys only once for each wallet, how often do i need to export keys for each wallet ??
Cheers
Backup should go on reliable flash memory in a safe deposit box, at the very least. You need to re-export private keys for each wallet each time you add a new address to it (as each private key is tied to its own address). If you have funds in addresses A, B, and C, make a backup, and create a new address D, receive money to it, and have a disk failure with no recovery, you'll be able to recover the balances of A, B, and C, but not D.
