It may work out if its your private laptop and no one else has access to it, otherwise i will recommend you to use a physical wallet, they are more secure and personal.
Yeah, but he is using an "old" laptop.
What if his old laptop is infected with a rat? or any other shit that maybe can compromise his bitcoins/coins that he is going to store?
I would prefer to spend $100 and buy a ledger wallet.
If you format hard disk of that laptop and freshly install operating system, then there will not be any malware or viruses. Some coins don't have wallets for Ubuntu. But if you have such coins that are compatible with Ubuntu, I would choose it over Windows.