Windows 7 64 bits - Diagnostic Policy Service does not start - Error 5 Access is Denied


I am getting the Diagnostic Policy Service Error 5 Access Denied. I cannot start the service no matter what I do. I have done all of the following with no success and need an urgent advice as gone thru lots of forums unsuccessfully.

1) Have used subinacl tool to reset my security permission on all registry folders granting full access to Administrators and System without any success

2) Have started my pc using MSCONFIG in minimal configuration diabling all non microsoft services and it did not solve my issue.

3) I have tried to Add/remove a feature in Windows like Windows Media Player and when the system shuttdown it displays a msg saying Windows Failed to configure your system for the new setting, windows will revert to previous state. and the Media Player is still showing.

The Fact that Diagnostic Policy Service is not starting is preventing me from using my Dial-up connection using a wireless modem using the PC Card it gives me Error 797 Port not available. My dial up connection's property show in the General Tab under Connect using it says: Removed Unailable Device (). So I do not have internet on the PC Card although the Device is detected by Windows and I see it as Iburst Terminal.

I also have an Issue, When I click on Phone and Modem in the Control Panel I get following Error: Phone and Modem Control Panel cannot be opened. You may have a problem starting telephony Service.

I checked Telephony Service it is set to Automatically and it is started. (I tried stop/Start) but did not solve my issue.

Any Help on this is much appreciated.




Dear I.  Suuresh Kumar,

Your silence to my 2 post left me with no other choice but to do a Windows 7 Upgrade Repair. For people running same issue I found that it was the only alternative as none from Microsoft could give me an answer. I found a post that explains how to go about doing an Upgrade Repair which for me ran from 1:30 pm and finished completly and successuflly at 8:00 PM.

What it does it re-installs a clean Windows version and keeps all your programs/settings/drivers/logins etc ... intact. It was my solution. Now my system is clean and with no problems. tks to the following link.

All this is thanks to Kevin Support Engineer at Microsoft. Many thanks Kevin



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Last updated May 22, 2020 Views 29,918 Applies to: