What’s the best software to remotely control my dad’s PC?

GoToAssist is another solid option. It allows for unattended installation so you can access his PC without him needing to approve anything, which can be really convenient.

Anydesk is worth trying, I’ve personally found it quite user-friendly. Also, I’ve been using NoMachine for a while, and it works pretty well—even when you have multiple machines in the same network.

If he's using Windows, Quick Assist could be a great fit. It’s straightforward and requires just a Microsoft account to get started.

I'd recommend using Chrome Remote Desktop. It's simple to set up and works quite well for remote access. Also, consider introducing him to the BeMyEyes app, where volunteers can offer assistance through video calls—it's a fantastic resource for blind users without putting too much responsibility on him.

You might want to check out RustDesk or AnyDesk. They're both free, super fast, and can be configured for unattended access, meaning once you set it up, he won’t need to do anything for you to help him. Just install it and set a password, and you’re all set!