How to fix Error 5: Access Denied when trying to run Diagnostic Policy Service and reconnect to WiFi.

Hello. I'm Douglas, here to help you with this.


STEP 1. SCAN FOR VIRUSES/MALWARE.
Viruses or malicious programs can cause your PC to work abnormally. So, before you continue to troubleshoot your problems, use this Malware Scan and Removal Guide to check and remove viruses or/and malicious programs that may be running on your computer.

STEP 2. MODIFY DIAGNOSTIC POLICY SERVICE REGISTRY PERMISSIONS.
1. Simultaneously press the Windows image + R keys to open run command box.
2. Type regedit and press Enter.
3. At the left pane, navigate to this key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DPS\Parameters
4. Right click on the Parameters key and select Permissions.
3. At the left pane, navigate to this key:
5. Click Add, type your account name/username in the search box and click OK
6. Select your username and check the Full control box to grant to your account full control permissions on the 'Parameters' key and click OK.
7. Then navigate to this key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\WDI\Config
8. Right click on the Config key and select Permissions.
9. Click Add, type NT Service\DPS in the search box and click OK.
10. Select the 'DPS' and check the Full control box.
11. Click OK and then close the registry editor.
12. Restart your computer.
13. After the restart, check if the "Diagnostic Policy Service Cannot Start" issue, was resolved.


I hope this information helps you, post the results again, I'm available.

Thanks.