I'm thinking about installing Windows 10 besides Ubuntu to be able to play every game from my Steam lib. I've googled how to do this properly but I didn't find stories of what can go wrong.

Does anyone has experience with that?

You could end up with windows 10

Win 10 should be installed first, dunno if this is still a thing

I just built a separate computer for games.

Easiest way is to install a second hd.

AFAIK Win10 still tends to randomly format/override non windows installations on the same system during updates.

@SortOfTested sanest option available. My CMS administrator managed to get them both working, even hasa customized boot loader which I honestly have no clue how he did.

If on a desktop you can always have two drives no?

I am not a hardware guy at all :V

It's probably still easiest to have them on two separate drives. And physically disconnect the linux drive when installing windows so the installer can't touch anything it shouldn't. Hopefully we're not talking about a laptop here.

@nitwhiz it's still a thing.

Windows ignores grub and sets windows boot manager as the ONE boot manager.

It can be repaired manually but IMHO it's just less hassle to install windows then reinstall Linux

Windows installer replaces Linux's bootloader (eg. Grub) with Windows Bootloader. So after installing Windows along side Linux, you might need to boot to Linux with USB installation media and reinstall Grub or your other preferred Linux bootloader.

Try installing refind as a bootmanager inside Windows's Boot drive.
That way you can dual boot while having secure boot on.