Storing my bitcoins on an offline computer I have a mac that I never use, would storing my bitcoins on a wallet on that laptop and then only connecting it to the internet when I am ready to transfer money be safe? Is there any reason not to do this? That way I don't have to worry as much about viruses infecting it and stealing my bit coins?

Also, what happens if I back up a computer, load it onto a new hard-drive, then open up that computer and run it's wallet, then open the original computer and run it's wallet.. now I have two duplicate wallets on two separate computers? Would I get an error from the P2P network or would I have duplicate coins (I'm assuming the second is obviously not the case)
I have a mac that I never use, would storing my bitcoins on a wallet on that laptop and then only connecting it to the internet when I am ready to transfer money be safe? Is there any reason not to do this?


Your laptop needs to catch up every time you want to make a transaction, which is not good.

The ideal solution would be Bitcoin Armory, which is designed for this type of thing:

How to sign a transaction using only an offline computer?

Find the mac version here - but note that it's in beta, hence why it's not on the main site.


  Would I get an error from the P2P network or would I have duplicate coins 


The second time you spend the coins, other nodes will reject it.