User no longer have the "not responding" issue when opening and working with PDF files.
However, it seems there is an error keeps showing everytime when he startup the computer. The error message is AcroCEF.exe - Application Error: The application was unable to start correctly (0xc0000142).
I tried repairing and also re-installing Adobe but the issue somehow still persists.
Any other advice for this? I have also attached the error message.