hello i aim to install a bitcoin wallet offline on my hard disk drive. But i also want other altcoins offline wallet. So may i install many cryptocoins offline wallet on the same drive ? or do i have to buy for each cryptocoin a single drive ?
Since I am not expert in offline wallet but here i will advise for cryptocurrency to save At exchange , Because I think there is risk to loss anything ( but you should keep in your mind the matter of Poloniex )
This is the worst advice every, saving to exchanges as they tend to get hacked (for me it's always an inside job) but let's call it they will be hacked. Never trust an online web wallet like blockchain.info, Xapo etc as you are relying on third party to keep the coins for you and to do any transaction you may want to do. They can also have technical problems.
The best desktop wallets are Electrum and Multibit HD (Electrum clearly the better as not as many bugs as Multibit lately). And if you want the best protection buy a cheap hardware wallet.