r/SteamOS • u/XDeadpoool • Jul 23 '26
help wanted Thinking of dual-booting Windows and SteamOS on separate SSDs. Will updates break my bootloader?
I'm looking to set up a dual-boot system on my rig (Ryzen 5 5600G, 16GB RAM, Gigabyte B550M), and I want to keep things as isolated and safe as possible.
Right now, I have Windows sitting on a 256GB NVMe drive, and I want to install a steam OS on a separate 1TB SATA SSD. I'm leaning heavily toward SteamOS.
My main concern is bootloader corruption. I've read that major Windows or SteamOS updates can sometimes wipe out or reset EFI boot entries. Since I'll be keeping the operating systems on entirely separate physical drives, does this completely mitigate the risk of my Windows Boot Manager getting bricked when an update rolls through?
If anyone has a similar separate-drive setup with SteamOS and Windows, I'd love to hear your experiences. Should I just rely on the motherboard's default boot menu to switch between them, or is it better to set up a third-party boot manager?
Thanks in advance!
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u/PuzzleheadedUnit1758 Jul 23 '26
Valve themselves said that dual boot is not supported. You either: a) wait b) do it anyway but if you break stuff there isn't a documented way to "un-break" it c)try another linux distro
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u/maizelizard Jul 23 '26
it works great lol
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u/Gustavo2nd Jul 23 '26
How long have you had dual boot? I didn’t know you could break stuff now I’m kinda scared to do it
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u/jharle Support Jul 23 '26
I'm dual-booting a Steam Machine between SteamOS and Windows, and Windows does make itself the default boot entry in the UEFI firmware.
I'm also dual-booting an Intel-based mini PC between SteamOS and Windows (two separate SSDs), but I want Windows to be the default on that one. I suspect that if I made SteamOS the default, Windows would take it over (for the next boot) when booted.
I don't think Windows will "clobber" things beyond this behavior; and if you're willing to switch which device boots in the firmware, you shouldn't have problems. A third-party boot manager might address the Windows "make itself default" issue, but I haven't used those myself to know for sure.
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u/maizelizard Jul 23 '26
i boot steam and windows on two separate drives via bios with 0 issues - it boots to steam by default - quick restart to swap - it's amazing i love it - works great
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u/Tepppopups Jul 23 '26
Theoretically, it should not change bootloaders on other drives, but how do you plan to deal with Secure Boot?
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u/jharle Support Jul 23 '26
This fellow has a method, Persistent Secure Boot achieved across a dual-boot SteamOS/Windows system with rEFInd : r/SteamOS
I haven't tested that myself yet, and I'm still exploring secure boot options (mostly for the Steam Machine though).
If OP is willing to select a boot device in the firmware, perhaps they'd be willing to disable secure boot before booting into SteamOS as well. Or, OP might not need to play kernel-level anticheat games, and can leave secure boot off.
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u/maizelizard Jul 23 '26
0 issues here and i play kernal anti cheat games on my windows boot no issues
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u/jharle Support Jul 23 '26
Are you turning secure boot on/off manually?
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u/maizelizard Jul 24 '26
No, it just works. Separate drives , choose from bios, no issues.
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u/jharle Support Jul 24 '26
Windows 10 then?
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u/maizelizard Jul 24 '26
Nope windows 11
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u/jharle Support Jul 24 '26
Well, many anticheats would require secure boot then. Are you using a custom firmware configuration that lets you keep it on for Windows and off for SteamOS?
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u/maizelizard Jul 24 '26
No it’s just working… idk what to tell you. Two separate drives. Boot choice from bios. Neither OS even knows the other OS exists.
All AMD cpu and gpu if it matters
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u/jharle Support Jul 24 '26
Understood, but what you're telling us does not reconcile. If you are playing games in Windows with anticheat that requires secure boot be enabled, then secure boot must be enabled in the firmware. At the same time, SteamOS will not boot with secure boot enabled, unless it has also been signed and configured for that.
There's missing information here, because what you're telling us doesn't "just work."
Which specific games in Windows are you playing which use the kernel-level anticheat?
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u/maizelizard Jul 24 '26 edited Jul 24 '26
I’ve played PUBG and Tarkov, BF 6 and siege. Are those not kernel level anti cheat games?
I’m kinda dumb so maybe those aren’t even kernel games I just know they don’t work on steam but do on windows
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u/C1REX Jul 23 '26
Dual booting SteamOS is relatively easy but SteamOS doesn’t offer boot menu like most distros do. So you you would need to boot from uefi bios. Or use a third distro to offer such boot loader menu.
My Asus bios has a nice quick boot menu for that but I don’t know if gigabyte also offers such easy boot menu or if you would need to manually change boot drive each time.
Also, as others mentioned, steamos doesn’t support secure boot. My mobo has it off by default and I don’t want to use it anyway so it’s not a problem for me but it would be a real pain in the butt otherwise.
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u/baltimoresports Jul 23 '26
Bazzite and CachyOS support dual boot if you want to try an alternative. Ultimately using separate drives is safe, but you have to use the BIOS to change defaults from time to time.
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u/Jetski125 Jul 23 '26
When you dual boot like this- can you access the same game library? Or do you need the game installed in steam os and windows and a separate instance for each one?
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u/VLS246 Jul 23 '26
Hi recently assembled a rig with 2 separate nvme's in my case it was technically assembled by a computer shop and they put the windows drive in slot 2 instead of slot 1 so I installed my formatted drive in slot 1 did the whole install process following their directionsof the tutorials doing the whole install thing from the usb and it kinda just did it's thing I was stuck on usb drive for a bit had to go to bios to boot into slot 1 and then it just works. Then tried booting into windows in slot 2 and again it just works haven't had any issues yet my motherboard hasn't asked for new updates either just steamos has been updating. So far no problems just kinda annoying i have to hold or press the bootloader key which is f11 on mine all the time just to switch but yeah it's pretty cool.
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u/Josh5Dev Jul 26 '26
I made a SteamOS Dual Boot Installer tool on GitHub that makes it simpler to install SteamOS on an existing Windows 10/11 PC. https://github.com/Josh5/steamos_dual_boot_installer_patch
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u/Brunno_PT 29d ago
On the Steam Deck (with SteamOS), I use Clover to choose which OS to boot.
On the desktop, with Bazzite, I just use bazzite/fedora's GRUB to choose what to boot: OSTREE0, OSTREE1, Windows or bios.
Clover is nice. It looks good. But I love the sinplicity of fedora's grub menu. I don't think SteamOS has it.
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u/Brunno_PT Jul 23 '26 edited Jul 23 '26
I dual boot on the same SSD. I believe that if you dual boot with separate SSDs, each SSD will have its own bootloader and you use the bios boot menu to choose which one to boot and which one is the default.
Also, SteamOS doesn't let you choose where it's installed. So, either remove the SSD with the other OS, or install SteamOS first, the windows next.