I setup a brand new Dell Dimension E520 for one of my clients a few months ago.  It was running Windows Vista Ultimate Edition.  I got everything setup without a hitch until I tried to install AVG Free.  After I installed AVG I kept getting the following error when the computer started up as well as when I tried to double-click on the desktop icon to start AVG:

avgwb.dat - Application Error
The application failed to initialize properly (0xc0000022). Click OK to terminate the application.

I tried all kinds of things to try to troubleshoot the issue.  I uninstalled AVG and reinstalled it.  I right-clicked on the AVG icon and selected “Run as administrator” which prevented the error from coming up but wasn’t a permanent solution.  I contacted Dell technical support because it was a brand new computer and I figured the problem was caused by something Dell did when they configured UAC in Vista.  I even purchased AVG Anti-Malware Edition and contacted Grisoft’s technical support team (the free version doesn’t come with technical support).  However, nothing I tried seem to help.  I finally decided that I needed to find a temporary solution and revisit the problem after Grisoft’s technical support team had more time to analyze the problem.  Since the problem seemed to be a security related issue caused by UAC in Windows Vista I temporarily disabled the UAC.  That temporarily “fixed” the problem and got AVG working until I could find the cause of the problem and fix it.

The Grisoft technical support team never did find a solution for me and Dell wasn’t much help at all.  Apparently they were all as baffled as I was.  When I was looking at the computer again today I noticed that the AVG error was coming up again.  It looked like someone had enabled UAC since the last time I looked at the computer so I decided to take another crack at the issue.  When I figured out the solution I decided to post it on my blog to help other people troubleshoot similar problems and hopefully save them some of the frustration I experienced.

The Solution:

I already knew the problem had something to with the avgcc.exe program not being granted the proper security permissions to run.  I did a little more research on the Internet and decided to use Dependency Walker to try to figure out what files avgcc.exe was having trouble accessing.

1. I downloaded Dependency Walker and extracted it.
2. I ran Dependency Walker and opened the “C:\program files\Grisoft\AVG7\avgcc.exe” file with it.
3. At the bottom of the screen it told me there was an access denied error when trying to load the “C:\windows\system32\mfc71.dll” file it was dependant on.
4. I opened Windows Explorer and browsed to the MFC71.DLL file, right-clicked on it, and selected properties.
5. Then I clicked on the Security tab.  It gave me a UAC security warning about changing the permissions of system files and I clicked Continue.
6. I added the Everyone group and gave it Read/Execute access to the file.
7. I tested AVG and it was working just fine after that.
8. I went back in to check the settings of some similar files and it looked like the previous permissions had been correct.
9. I removed the Everyone group and tested AVG.  It still seemed to be working ok so I rebooted to double-check and everything came up just fine.

Conclusion:

It looks like the permissions for the MFC71.DLL file got corrupted somehow.  I don’t know if it was something wrong with Dell’s original setup or what caused the problem.  I haven’t ran into this problem on any other Dell computers running Vista yet.  If you have ran into the same problem before please post a comment and let me know.  I’d really appreciate the feedback.  Thanks!