When attempting to open the control center, I received the following error message:

avgcc.exe Illegal System DLL Relocation

the system DLL user32.dll wsa relocated in memory. The application will not run properly. The relocation occurred because theDLL c:WINDOWS\system32\SMLL32.dll occupied an address once reserved for windows system DLLs. The vendor supplying the DLL should be contacted for a new DLL.

What should I do? I was able to run a virus scan, but the icon doesn't appear any longer on the lower right hand corner of the screen.

There is a very high likelihood that the file smll32.dll is malware of some sort, and deliberately interfering with AVG. That file is absolutely not a valid system file. I strongly recommend that you follow CastleCops' Malware Removal and Prevention procedure, a system CastleCops devised to enable users to either partially, or fully clean their systems without the direct aid of an expert.

Please read these instructions carefully. You will find the Malware Removal and Prevention Procedure here:

http://wiki.castlecops.com/Malware_Removal_and_Prevention:_Introduction

If that doesn't fix the problem, then go to this Forum, read the instructions at the top of the page carefully:

/f67-Hijackthis_Spyware_Viruses_Worms_Trojans_Oh_My.html

Follow these instructions:

/t102301-Hijackthis_Guidelines_Read_Before_Posting.html

and one of CC's trained 1st Responders or Security Experts will help you. I suspect that you will probably need live expert help to fix this problem and rid your system of malware.

Note: You must be a CastleCops member to post for help in the HJT forum.

I goofed! It isn't "c:WINDOWS\system32\SMLL32.dll" it is "c:WINDOWS\system32\SHELL32.dll". Does this make a difference?

Yep, a big one - unless shell32.dll has been replaced by malware, that is a valid Windows system file. Having said that, I still do recommend that you start down the possible malware route anyway since several forms of malware do interfere with anti-malware products like AVG's. On the other hand, it is also entirely possible that the file may be corrupted, or other non-malware related issues may be causing the problem, including possibly that your AVG install has gotten corrupted. That happens.

I ended up removing AVG and installing another anti virus software. Seems to work fine. However, today I tried to back up the computer using Acronis. I received the same error message and I can't back up. Now what??

Strange. Go to Start, then click on Run. Copy and paste the following command:

sfc /scannow

into the Run box, then tap <Enter>. Tell me what, if anything, it finds.

When it completed the check, window just closed, no message, nothing.

Apparently this is a Microsoft update problem. See link:

http://support.microsoft.com/default.aspx/kb/935448/