I have Linux installed on the main SSD; for some things though it would be nice to be able to access native Windows. If I get a storage expansion card will it be able to run from there?
I would expect to use GRUB on the main SSD to choose whether to continue booting Linux from that or the Windows install on the expansion.
In my experience installing Windows, the official Windows installer does not recognize external storage.
I used an expansion card to run windows for a while. It worked pretty well, although disk heavy tasks would often be slow or slow to start.
You will need to use something like Rufus to make a Windows-to-go installation on the card: https://rufus.ie/
I’ve been running Windows 11 off of an expansion card for about a year without any issues (besides things that happen with any dual-boot setup, because I have Pop OS on my internal storage). Creating the Windows To Go drive was very straightforward with Rufus. I have an 11th gen motherboard (i7-1165G7).
Windows 11 has been working mostly fine for me after using Rufus to set it up. The only real problem is that it can’t seem to reboot, the screen goes black but the laptop keeps running until you force it to shut down. Annoying, but I only have Windows on a card to use it when I need it once and a while, so tolerable.