Windows 10 screen resolution reverts to 1024x768

[llamahunter]

I am running a Windows 10 Preview guest in an OSX 10.10.3 host, using VirtualBox 4.3.28.

When I first launch the guest, I am able to put it into fullscreen mode and it consumes the entire 1920x1080 screen. A short time later (measured in tens of minutes), the guest reverts its size to 1024x768, and refuses to budge. In fullscreen mode, it is a small rectangle in the middle of the screen. In windowed mode, it is a window that, when resized, does not resize the guest (despite the fact that 'Auto-resize Guest Display' is enabled in the View menu).

If I warm reboot the guest, it comes up stuck at a *different* resolution of 1280x960. I have to cold boot it (i.e. shut down the VM entirely, and then restart it) for it to return to 1920x1080, but then, it only stays there for 10-20 minutes before reverting to 1024x768.

Any ideas what to do to fix this? I do not have 3D or video acceleration enabled in Virtualbox, and have 128MB of video ram.

[llamahunter]

Also note that I have a Windows Vista guest configured with this same VirtualBox installation with similar configuration that runs at 1920x1080 just fine, and has for years.

[loukingjr]

With the guest shutdown (not Saved State), attach "vbox.log" (compressed) for the guest to a message here.

I have Windows 10 (build10130) installed as a guest on three Macs…
iMac - OSX 10.11 B2 - VB 4.3.28 - ok
MacBook Air - OSX 10.10.3 - VB 4.3.28 - ok
MacBook - OSX 10.10.3 - VB 5.0 RC2 - ok

Windows 10 does not leave full screen on any of them. The difference may be I have 2D and 3D enabled for all three.

[@VBLinux]

You installed the VirtualBox Additions ?

[loukingjr]

If you are asking me, yes.

[@VBLinux]

So i dont find the problem, sorry :/

[loukingjr]

No need to be sorry. First of all when I answered I was on a OSX host. Someone may still have an answer. Attach the vbox.log (compressed) for the guest here.

[Carlos D.]

Have that experienced, too (Win10, and even occasionally when testing Server 2012R2).

If that happens again, open Device Manager, and you'll probably see that the VBox display driver has crashed with code 43. Windows only tells that the driver stopped working and had to be disabled. No need to reboot, just disable and re-enable the crashed driver. In the long term, that issue needs fixing, however.

[llamahunter]

Have that experienced, too (Win10, and even occasionally when testing Server 2012R2).

If that happens again, open Device Manager, and you'll probably see that the VBox display driver has crashed with code 43. Windows only tells that the driver stopped working and had to be disabled. No need to reboot, just disable and re-enable the crashed driver. In the long term, that issue needs fixing, however.

Yes, this seems to be the case (driver is crashed). Disable and re-enabling gets back to 1400x1050, but not all the way to 1920x1080. Seems like there's a bug in the vbox guest additions in windows 10.

[loukingjr]

Seems like there's a bug in the vbox guest additions in windows 10.

As I mentioned above i have Windows 10 (now build 10240) installed on three different Macs. Two have been updated to OSX 10.10.4 since. I can't reproduce your problem on any of them. I did just notice however Windows 10 takes up a lot of memory. I did have it set to 2048MB RAM and 128MB VRAM but noticed in the Task Manager that just opening Firefox took up 66% of the RAM so I've increased it to 4096MBs and 256MBs.

I ran it this morning for about an hour or so in full screen and it still doesn't revert.

Attach the vbox.log (compressed) in a message for your W10 guest.