I used to mine bitcoins and stopped about two years ago. At that time I was using Bitcoin-QT 0.8.5 Beta. The computer has been powered off since then, and my wallet.dat is still on that computer.
Can I still use that version, or do I have to upgrade to the latest Bitcoin Core? Besides backing up my wallet, should I do anything in preparation before I reconnect the old computer to the Internet, or before upgrading software? It says the wallet is out of sync and the block is 95 weeks behind.
Any guidance will be appreciated.