How to Enable or Disable Program Compatibility Assistant in Vista, Windows 7, and Windows 8
Information
The Program Compatibility Assistant (PCA) runs in the background and monitors user initiated programs for known compatibility issues at run time. Whenever a potential issue with an application is detected, the PCA will prompt the user with pointers to recommended solutions.
This tutorial will show you how to enable or disable Program Compatibility Assistant (PCA) in Vista, Windows 7, and Windows 8.
Turning off PCA is useful for system administrators who require faster performance and are aware of the compatibility of the applications they are using.
Note
With the PCA turned off, users will not be presented with solutions to known compatibility issues when running applications.
Warning
The Diagnostic Policy Service (DPS) and Program Compatibility Assistant Service must be set to Started and Automatic in Services for the PCA to be able to be enabled and to execute.
EXAMPLE: Program Compatibility Assistant Warnings NOTE:These are some examples of the warnings that PCA may give you if it detects a compatibility issue with a program. You can read more about these here: Application Compatibility: Program Compatibility Assistant (PCA)
OPTION ONE
Using a REG File Download
1. To Enable Program Compatibility Assistant NOTE:This is the default setting.
A) Click on the Download button below to download the file below.
Enable_Program_Compatibility_Assistant.reg
B) Go to step 3.
2. To Disable Program Compatibility Assistant
A) Click on the Download button below to download the file below.
Disable_Program_Compatibility_Assistant.reg
3.Save the .reg file to you desktop.
4. Double click/tap on the downloaded .reg file to merge it.
5. If prompted, click/tap on Run, Yes (UAC Windows 7/8) or Continue (UAC Vista), Yes, and OK.
6. Restart the computer to fully apply.
7. When done, you can delete the downloaded .reg file if you like.
2. In the left pane, click on to expand User Configuration, Administrative Templates, Windows Components, and Application Compatibility. (see screenshot below)
3. In the right pane, right click on Turn off Program Compatibility Assistant and click on Edit. (see screenshot above)
4. To Enable Program Compatibility Assistant
A) Select (dot) either Not Configured or Disabled. (see screenshot below step 6) NOTE:Not Configured is the default setting.
B) Go to step 6.
5. To Disable Program Compatibility Assistant
A) Select (dot) Enabled. (see screenshot below step 6)
I took your reg key and made a VB script for Windows 7:
Dim WshShell
Set WshShell = WScript.CreateObject("WScript.Shell")
WshShell.RegWrite "HKCU\Software\Policies\Microsoft\Windows\AppCompat\DisablePCA",00000001,"REG_DWORD"
I also added to my script the program compat Flag, in my case Visual studio 2005:
I needed this script so that i could deploy windows 7 and Visual studio 2005 using MS system center.
I couldn't use group policy because the visual studio installer runs as part on a task sequence to install windows 7- group policy don't apply until after this has completed.
So the script could be used as part of windows 7 & software deployment.
System Manufacturer/Model Number HP pavillion dv2910tx OS windows 7 Memory 3GB Graphics Card Nvidia Gforce 8400 series 128mb Screen Resolution 1200x800
Almost. While both will stop the Program Compatibility Assistant Warnings, disabling the "Diagnostic Policy Service" may cause unknown issues though since it is not disabled or stopped after applying any of the methods in the tutorial. I would recommend using one of the methods in the tutorial instead.
System Manufacturer/Model Number Gateway/NV7923u & NV79C52u Laptops OS windows 7 professional & ultimate 64bit laptops CPU 2.27 boost to 2.53 & 2.53 boost to 2.80 Motherboard Mobile Intel® HM55 Express Chipset ??? Memory 4GB Graphics Card Intel® Graphics Media Accelerator HD Sound Card realtek High-definition audio support Monitor(s) Displays 17.3 " HD 1600 x 900
Hard Drives hatachi Travelstar 5400 500GB & west digital 500GB Internet Speed 35MB fios
System Manufacturer/Model Number Gateway/NV7923u & NV79C52u Laptops OS windows 7 professional & ultimate 64bit laptops CPU 2.27 boost to 2.53 & 2.53 boost to 2.80 Motherboard Mobile Intel® HM55 Express Chipset ??? Memory 4GB Graphics Card Intel® Graphics Media Accelerator HD Sound Card realtek High-definition audio support Monitor(s) Displays 17.3 " HD 1600 x 900
Hard Drives hatachi Travelstar 5400 500GB & west digital 500GB Internet Speed 35MB fios
Information
Note
Warning
OPTION ONE 
Quote: Originally Posted by Woundman 
My first encounter with Program Compatibility Assistant... 
