All of a sudden today, I booted my Windows 7 machine and got the following message when Steam tried to run:
So I checked the properties for Steam.exe and found that compatability mode was off:
Thankfully fixing this problem was quite straight-forward though:
- Click Start, type regedit and then press the Enter key
- In the left hand pane of Regedit navigate to the following key: HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
- In the right hand pane delete the string for Steam.exe
Once I had done this I was able to start Steam normally.
According to Edugeek there is a second registry key that you can try if there is not a Steam.exe entry in the one listed above:
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
Thanks to Edugeek for the fix!