This was happening to my clients a lot, it was more often Outlook 2013 that caused the flickering, it was horrible though, enough to cause a seizure!
The operating system is Windows Server 2012 R2 fully patched up to date 2/3/2015
TSPlus is the latest version too 8.10.2.28
Office 2013 x86, also patched up fully.
at initial login there were no problems but after the users had been working 1-2 hours, outlook would start to freeze, the skin over it would appear to change to a 'basic' skin rather than how its supposed to look ,and then when clicked it would flash very rapidly, the user had to end the process to stop this.
anyway I was logged into a console as admin watching task manager. I noticed that each user has a 'Desktop Windows Manager Process, which is actually linked to an instance of DWM.exe running under a separate user on the system 'dwm-1' 'dwm-2' etc etc.
I noticed the CPU usage spiked on this to pretty much 12.5% (100% of 1 core).
I played about setting priority on certain users dwm.exe threads.
Setting it to Idle stops the freezing and flashing problems. Great I couldn't set process priority it for each user 'at login' because the users aren't admin and the dwm.exe runs under its own username.
In the end I fixed the problem by creating a scheduled task to run every 10 minutes as below :
wmic process where name="dwm.exe" CALL setpriority 64
This sets the priority of all DWM threads to 'idle' as in, use as little CPU as you can to stay running.
I had to set it every 10 minutes to it can catch new DWM threads as users log on and off throughout the day.
Problem solved
I hope others find this useful!
