High DPI scaling can be a pain sometimes, normally you just go to the EXE and turn it off manually. But how can you turn it off for a DLL file?

My problem is that I want to to turn it off for Windows Photo Viewer which it appears is a DLL file rather than an exe!

Why I want to do it for a Windows' own app? Well because sometimes their own apps don't work properly as they have admitted here.

Also, can someone tell me exactly which DLL file is Windows Photo Viewer. Different sources on the web give me these 2 files: (the first one looks obvious though!)

  1. C:\Program Files\Windows Photo Viewer\PhotoViewer.dll
  2. C:\WINDOWS\System32\shimgvw.dll
  • shimgvw.dll isn't Windows Photo Viewer. It is a file for Windows Picture and Fax Viewer which was part of Windows XP.
    – Ramhound
    Commented Sep 11, 2015 at 11:53

2 Answers 2


The problem of high DPI briefly explained:

According to this site:

The problem in Windows 10:
When you have a widescreen, with a resolution of 1920x1080 or higher or a bit lower, in Windows Vista, 7, 8 and 8.1 you would put your DPI scaling to 125% or higher to make text and images appear larger and more easy to read. But when you put the DPI scaling to 125% in Windows 10, you see in a lot of dialogs and windows the font gets very blurry.

And then it continues:

At some point we can understand Windows why they changed the DPI scaling in Windows 10. It is probably ment to support mobile devices more easy. But if you like to use your Desktop as a Desktop, and you demand high quality only. Then you can use this fix until Microsoft has addressed this issue.


So, if you use your Windows 10 only for a Desktop purpose, you can download their free program called XPExplorer from here.

Why use this program and not some registry change?

The site answers:

Why this is a small software program, and not some 'Registry Tweak' is because when you manually adjust the DPI settings at your 'Windows Registry'. Windows will reset your dpi settings every 2 reboots. Which means you would have to adjust the registry again (Microsoft forces you almost to use its new DPI scaling method).**

I can confirm this solution works well (as well after reboots) on my Windows 10 setup.

Good luck.


The dll file is located here in windows 10 : C:\Program Files (x86)\Windows Photo Viewer

Photo Viewer dll is launched by good old "rundll32.exe"

Looks like you can disable DPI scaling for "rundll32.exe" by adding the following registry key: "C:\Windows\System32\rundll32.exe" to

[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers]

and set its value to "HIGHDPIAWARE"

Source here

I haven't tried it myself yet as Win10 photo app does the work for me

  • I can confirm that this method does work. The value needs to be set to ~ HIGHDPIAWARE.
    – tomasz86
    Commented Apr 16, 2021 at 5:04

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