[Solved] Windows 10 2nd monitor stopped working after awhile.

[JohnNess01]

After upgrading to VB 5.1.22 and its Guest Addition, the 2nd monitor worked for couple of days and suddenly stopped. Everytime I try to detect, I get "Can't detect another display"
I tried to tweak the settings by adding extra graphics memory and enable/disable stuff but all in vain.

I think it's Windows 10 driver mess up. I have another vm for Win7 and it's working fine with the two monitors.

I searched this forum and other sites but all in vain.

Please advise!

Thanks.

[socratis]

the 2nd monitor worked for couple of days and suddenly stopped.

Something must have happened between the time that it worked and the time it didn't. Things don't change randomly...

Everytime I try to detect, I get "Can't detect another display"

Where do you try to detect the monitor?

I think it's Windows 10 driver mess up.

Is that your host or your guest? And if you're referring to Windows XYZ, remember it's a generic designation, a family. Please use specific versions. BTW, did you update Win10, or did it update itself? And that made it stop working?

[JohnNess01]

@socratis. Yeah, I believe something has happened, yet am not sure what. I had Windows Update disabled back then.

I get "Can't detect another display" when I try to extend my display to the second one, from the Display Settings. Windows displays the second monitor there, but it can't detect it.

Detailed specs of my setup:
Host: MacbookPro / 8MB of RAM / OSX El Capitan version 10.11.16
Guest: Windows 10 Pro / 32-bit,x-64 based processor / version 1607 / Build 14393.1358 / Intel(R) Core (TM) i7-5650U CPU @2.20GHz 2.20 / Installed RAM 3.50MB

I've enabled Windows Update recently, if it would make a difference.

Attached below is the Device Manager of the guest Windows machine.

[socratis]

Excellent, thank you. That pic from the Win10 guest is helpful, as it does show two monitors detected in the guest. I'll need a couple of things from you:

1. Start the VM. Not from a saved or paused state. Clean start.
2. Take the steps required to generate/observe the error.
3. Shut down the VM. Not saved or paused. Completely shut down.
4. Right-click on the VM in the VirtualBox Manager. Select "Show Log..."
5. Save it (only the first VBox.log), ZIP it and attach it to your response.

I would also like to see the "recipe" of the VM, the ".vbox" file:

1. Right-click on the VM in the VirtualBox Manager. Select "Show in Finder".
2. ZIP the selected ".vbox" file and attach it to your response.

[JohnNess01]

@socratis Thank you again for your detailed reply.
I followed your instructions and kindly find attached the documents you requested.

[socratis]

00:00:02.164148 Guest OS type: 'Windows7_64'

You need to change the VM OS version. You're not running Windows 7 anymore...

00:00:02.210875 File system of '/Users/John/VirtualBox VMs/win10-parallels win7 clone/Snapshots' (snapshots) is hfs

I'd like an explanation about the name of the VM. Was this a Parallels Windows 7, which got cloned and upgraded to Windows 10? The fact that your main hard disk is an HDD (parallels disk) seems to support that theory. Have you uninstalled the Parallels tools (if any)?

00:00:02.182156 GUI: UIMachineLogicFullscreen::sltHandleNativeFullscreenWillEnter: \
                Machine-window #0 will enter native fullscreen

Could you start your VM normally? Do you have two physical monitors? If you don't, things aren't going to be right. How are you going to manage two virtual monitors full screen when you only have one physical monitor? In any event, try NOT to start the VM in full screen mode, but once you've set everything up, that should be your last step.

00:00:02.138528 Host RAM: 8192MB (8.0GB) total, 4123MB (4.0GB) available
00:00:02.334329 RamSize  <integer> = 0x0000000140000000 (5 368 709 120, 5 120 MB, 5 GB)
00:00:02.334644 VRamSize <integer> = 0x0000000009b00000 (162 529 280, 155 MB)

You are assigning memory to your guest, that you do not have available. Either close some applications on the host, buy more RAM for the host, or reduce the amount of RAM assigned to the guest. And since you want a couple of monitors and 3D, follow the advice given and increase the graphics RAM to 256 MB.

00:00:02.334326 NumCPUs <integer> = 0x0000000000000002 (2)
00:00:02.732376 CPUM: Logical host processors: 4 present, 4 max, 4 online, online mask: 000000000000000f
00:00:02.732381 CPUM: Physical host cores: 2

You have assigned all your CPUs to the VM. The host is going to run low on resources, since VirtualBox cares about physical processors, not logical ones. See: CPU Cores versus threads.

I've enabled Windows Update recently, if it would make a difference.

Try to re-install the Guest Additions. Win10 is a really weird OS and their updates break things. A lot.

[JohnNess01]

That was thorough!
Your guesses are right. It was a parallel Windows 7 machine, then I moved it to VB (I liked it more) and then upgraded Win7 to Win10, which could explain the mess.

Again, you're right with the memory assignment, the host machine fan has gone crazy since I tried to give the guest more memory. I did that the minute the 2nd monitor didn't work.

I'll follow your recommendations and let you know.

Thank you so much!

[JohnNess01]

IT WORKED!

Thank you so much@ socratis.

I did the following..
changed the settings back to 1 monitor,
couple of restarts,
changed it back to 2 monitors,
exit fullscreen mode,
enabled second monitor from the View menu,
and voila!

[socratis]

Ta-da!!! . Glad you got it working.
Marking this as [Solved].