hi everyone! i’ve heard recently about some issues caused by windows when dual booted with linux. i have both systems on separate physical drives. i actually upgrade my new laptop’s win 10 to win 11. i hardly ever use windows. manjaro is my daily driver. so after my upgrade i removed the laptop’s nvme and pluged it on my desktop alongside my manjaro. suddenly i noticed that windows appeared on the grub menu. can it cause any harm if i’ll boot to windows? as i said, the systems are installed on two different SSD. thanx on advance!
1 Like
If your grub is up to date and you dont use crowdstrike then whatever you heard is probably unimportant…
The same things still apply as they always did - malware in your windoze or doing something using windoze (such as reformatting partitions) can have adverse affects. And of course windoze will be windoze and may sometimes hijack the boot loader (this is usually just a matter if setting grub to be default again)…
Otherwise, no, booting your windoze will only have the usual side effects including but not limited to higher power consumption and raised blood pressure.
This? “Something has gone seriously wrong,” dual-boot systems warn after Microsoft update | Ars Technica
A update-grub during a system update probably added the Windows entry to GRUB.
Not more than usual, besides this update in the article but it should not affect Manjaro as we don’t use Secure Boot here… but maybe it will, just try.
Exactly. If it is disabled it does not matter if it is broken.
I also have it disabled, but I find it great that Manjaro does have secure boot support.
No, it doesn’t. You can use Manjaro in combination with Secure Boot if you’re willing to put in the work — the Arch Wiki has information about how to get it working — but Manjaro does not officially support Secure Boot, and also has no plans of doing so in the future.
I had the “support” italicised, but maybe I should have been more clear.
I note that most responses above seem to have missed that you have moved the Windows NVMe from your laptop to your desktop machine.
This is generally the safest method of multibooting; with each OS on a separate disk, largely (but not completely) isolated from the affects of another OS.
So, to be clear, you have Windows installed on a removable USB, which you plugged into your desktop machine, is that right? Or, did you physically connect the NVMe module to your mainboard?
Although, the question remains; why have you done that, in any case? 
This would be expected, as os-prober (when installed) automatically detects any viable bootloaders and allows Grub2 to list it; so, that includes Windows.
Yes, it can, potentially.
Although, Windows is typically able to recover after many driver changes and reboots.
The problem is that you installed Windows on your laptop – completely different hardware than your desktop – while Windows can recover from this, it’s not always a smooth process.
However, if you then wish to place Windows back in your laptop you may face additional complication as Windows (again) has to reconfigure for the previous hardware.
Basically, yes you can do it, but expect problems.
Manjaro, however, should be largely unaffected; as long as the usual prerequisites are attended to:
SecureBoot
SecureBoot must be disabled – Manjaro does not support it, and cannot easily co-exist with Windows when it’s enabled. Now, as you have Manjaro installed already, that’s probably not an issue, although Windows will likely complain.
UTC vs. Local Time
Linux (and macOS) default to setting a computer BIOS clock to UTC, the primary global time standard, whereas Windows (unsurprisingly) did not adopt UTC by default and uses the Local Time standard instead; similar to Standard Time.
This inconsistency causes particular annoyance in a multiboot scenario, as each OS defaults to a different time standard, resulting in the BIOS clock being reset on every boot/reboot.
The lack of UTC support in Windows (by default) is a fundamental design flaw, or at the very least, an embarrassing oversight. Linux already handles UTC with superior grace - let Windows in turn assume the ‘burden of repair’.
An elegant solution is to create a Windows registry file with the following content;
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation]
"RealTimeIsUniversal"=dword:00000001
Create and save this file as RealTimeIsUniversal.reg.
After merging this registry entry, Windows will set the BIOS clock to UTC, and each OS will use the UTC time standard on subsequent reboots. This modification doesn’t affect your date/time display in Windows. Configure it as you would normally.
Fast Startup (Windows)
A hibernation variant known as Fast Startup may be enabled on Windows computers.
With Fast Startup enabled, Windows does not actually shut down; instead, it sleeps. When the computer subsequently wakes from the hibernation state, this gives the illusion of a faster startup and shutdown experience.
When multibooting, this can cause havoc with GRUB 2 and related boot processes, as well as NTFS mounting functionality, in Linux. To better understand these issues, and their consequences, please see the related article [Primer] NTFS on Linux.
Fast Startup must be disabled in a multiboot scenario. 
There are many documented ways to turn off fast startup in both Windows 10 and 11, however, the easiest is to use this command from an administrative command prompt to disable all hibernation (other sleep states will not be affected):
powercfg /h off
Create an Administrative Command Shortcut:
If you cannot seem to find how to access an Administrative Command Prompt in Windows, you can instead create a shortcut to cmd.exe:
- Right-click your desktop and choose New → Shortcut
- In the Create Shortcut dialog, input the location:
cmd.exeis all that is needed. - Click Next and input a name for the shortcut:
Admin Promptfor example. - Click Finish to finish creating the shortcut.
- Right-click the shortcut and select Properties.
- Click Advanced and click Run as Administrator (checkbox).
- Click OK, and then OK again.
I hope this information has been helpful.
Cheers.
2 Likes
thanks. back up first. LOL
i’m still using windows only for one reason. i’m into photography. i use all the great open source apps like rawtherapee and gimp to edit my photos. the only thing i needed to do in windows was my photo book printing. the book creator i used didn’t work on linux. funny, i contacted the company and they admit they are getting requests to release a linux version but they won’t do it. i searched and found a book creator for linux and i’m currently waiting for the first print. even if everything goes fine, i won’t be ditching windows anytime soon. i still have some book images in the previous format. i boot into windows once in a blue moon. i find linux a much better os. manjaro works best for me because i don’t need to wait for photography apps updates so long like i had to do when i used ubuntu based os.
i’ll try to deal with it. i’m a 65 years old retired truck driver and not an it engnineer but when i reach such problems i have some friends that are willing to assist. thanks a lot!
1 Like
Off topic:- Here’s something you might find interesting…
sudo pacman -S digikam
The name DigiKam may be confusing, however, it’s a fully featured graphics suite for Linux. It’s made by KDE, but is also standalone, which means to say you can also install it on other Linux desktops.
Most importantly, it has a Print Creator functionality under the Tools menu which you may find useful; plus many other capabilities too numerous to list.
I notice rawtherapee does have a version for Linux, albeit in .appimage format, nonetheless, this is certainly usable in Manjaro.
Was my previous post helpful for you?
You haven’t responded to it at all, so it’s difficult to know.
Cheers.
1 Like
yes! it was helpful. thank you very much. i was a bit overwhelmed by all the answers. I didn’t think anyone would show any interest in this topic. so i will use the opportunity to thank you all. i’ll look into digikam as well. i got the printed book today and it looks great! it’s the first book i created entirely on linux.
3 Likes
I’m guessing your post was meant for another thread, as it seems totally out of context here.
You might want to copy/paste it to the intended thread.
Cheers.