How to fix Windows 10 DPI scaling on virtual machines with high-definition displays

When Microsoft released the Windows 10 Technical Preview at the beginning of October, I decided that instead of installing the operating system on top of my current Windows 8.1 installation, using a virtual machine was be the safest test environment to run Windows 10.

While the Technical Preview installation completed successfully, my PC has a high DPI display (retina) and apparently there is a problem with virtualization software and Windows 8.1 and Windows 10 as I notice that the modern experience and the desktop Taskbar automatically adjust to look correctly on high-definition displays when using scaling, but the Start menu, apps, text, and other items in the screen do not scale properly.

Yes, you can go to PC settings > PC and Devices > Display and change the option to make everything a bit bigger. Apps, text, and other items in the screen will scale better, but you’ll notice that the Start menu hardly scales. I noticed this high DPI issue on retina displays on VMware Workstation, VirtualBox, and VMware Fusion on Mac.

Although there isn’t a permanent fix, there is a workaround you can use to make it all work well and that involves modifying a Windows Registry key.

How to fix high-DPI scaling issue with virtual machines

Open the Windows Registry (regedit.exe) as an Administrator and locate the following path:
```
HKEY_CURRENT_USER\Control Panel\Desktop
```
Look for the LogicalDPIOverride String. If you don’t see it, right-click New, select String Value, name it LogicalDPIOverride.
Double-click the LogicalDPIOverride String and change the value to the scaling setting you set Windows 10 in the Display settings from Control Panel. For example, if you’re using 150% scaling setting, the String value should be 1.5, if you’re using 200% scaling setting, you should set the value to 2 (you get the idea).
Once you’re done changing the Registry key, restart the PC or simply sign out and sign back in to see the new changes, and you’ll see this:

Instead of this:

I just showed you the instructions of how everything works, but there is always an easier way to do things. In the link below I created two .reg files that you can download to change the scaling settings in Windows 10 automatically. Use the “fix-dpi-windows-vm_pureinfotech-enable.reg” to turn on the setting and use the “fix-dpi-windows-vm_pureinfotech-disabled.reg” to turn off the setting.

Keep in mind that the .reg file to fix the DPI settings in Windows 10 using a virtual machine is configured to scale to 200%. If you wish to have a different configuration, you’ll have to edit the file using Notepad and changing the LogicalDPIOverride setting to the number you want before merging the settings to the registry.

Important: Use these instructions as your own risk, modifying the registry can cause damage to your current installation, as such you should only proceed if you know what you are doing. It’s always recommended to make a backup of your system before making changes. You have been warned!

It’s worth noting that this Windows Registry tweak works in Windows 10 as well as in Windows 8.x virtual machines running in VMware Workstation, VMware Fusion, VirtualBox in Windows and Mac.