virtualbox.org

apologies if improper, i don't have much experience with virtualbox.
Vbox 5.5.22; picked for Aero support on VM, which does have Guest Additions.
Host Win10 home 64bit 9GB RAM / Guest Win7 Ultimate 64-bit ~5GB RAM.
Every time I run the guest machine, somehow my host machine's GPU drivers get corrupted? Things like Steam Big Picture or Movie Maker stop working entirely, the screen briefly turning off then coming back on and showing a "D3D Device was removed due to DXGI_ERROR_DEVICE_RESET" error afterwards, while Discord or Firefox turn highly unstable when performing any video-related task. I have absolutely no clue why this happens. Only thing that seems to fix this is uninstalling the AMD drivers and reinstalling that. And also, the driver errors only seem to kick in hours after i boot and shutdown the guest. What the hell do I do?

I don't know if this explains the cause/solution to your issue, but there is some specific guidance in the VirtualBox User Manual on setting up a Windows 7 VM to use Aero. I don't have direct access to the User Guide for the version you're using (which you can access through the VirtualBox Help/Contents Menu), but in 6.1.4 it's in Hardware Accelerated Graphics, para. 4.5.1

Probably that's 5.2.22? Virtualbox 5 never got up to 5.5.x.

If you're turning on Aero in the guest OS, you probably have enabled 3D acceleration in the guest Video settings. 3D acceleration uses host video drivers to process guest 3D video commands. It could be that your host video drivers don't like Virtualbox using them and crash out.

While your guest is set up with the host-driver-disabling settings now, start the guest from full normal shutdown, not save-state. Run until you see the problem with your host video drivers happen, then shut down the guest from within the guest OS if possible. If not possible, close the Virtualbox window for the guest with the Power Off option set.

Right-click the guest in the main Virtualbox window's guest list, choose Show Log. Save the far left tab's log, zip it, and post the zip file, using the forum's Upload Attachment tab.