Windows 7 to be presise. I should make my own os and browsers. I dont like the current development of software. It's all adjusted to the menace of new phones and devices. I prefer programs that DONT suggest anything at all or updates that goes automatically. Screw security. I need my pc to stop trying.
If you want win7 or other systems, you can try vmware player free version for personal use .
Have fun kid and stay safe .