Tuesday, June 21, 2016

Fixing DPI Scaling Issues in Skype for Business on Windows 10

My setup for my day job these days is a Surface Pro 4 and either an LG 34UC87M-B or a Dell P2715Q monitor, depending on where I'm working. This is a fantastic setup, but some applications have trouble dealing with the high pixel density and don't scale appropriately.

One case in point is Skype for Business. For some reason it scales correctly as I move between the Surface screen and the external monitor when I use the Dell, but on the LG monitor Skype is either massive on the external monitor, or tiny on the Surface screen.

After a big of digging around I came across a solution that worked for me, which is to change a setting in Skype's manifest file (who knew there was one?). On my machine the file is here:
C:\Program Files\Microsoft Office\Office16\LYNC.EXE.MANIFEST

And the setting in question is this:
<dpiAware>True/PM</dpiAware>

Which I changed to this:
<dpiAware>False/PM</dpiAware>

Note that you'll probably have to edit the file as administrator in order to be able to save it.

Once I made that change, saved the file, and restarted Skype, it now scales correctly for both the Surface screen and the external LG monitor.

4 comments:

Matt Woodward said...

Turns out this didn't work after a reboot, even though the settings file stayed the same. It does work fine on the Dell monitor, but isn't happy on the LG for some reason.

Kim Rosgaard said...

Try this in addition to your change in the manifest file:
Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\SideBySide
Make a new DWORD named PreferExternalManifest and set the value to 1

Matt Woodward said...

Thanks for the suggestion! Didn't seem to work on my end but really appreciate the additional information.

Matt Woodward said...

Found something that's working for me at this point -- we'll see if it sticks.

1. Change the LYNC.EXE.MANIFEST file, set to True (I took out the /PM bit)
2. In regedit, find the lync.exe HIGHDPIAWARE key in HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers and delete it.
3. Change the permissions on HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers so your account doesn't have write access. This way the key won't get rewritten.
4. Restart Skype

Found the solution here: https://www.skypefeedback.com/forums/299913-generally-available/suggestions/9572103-skype-for-business-in-latest-2016-preview-still-no