I have the same problem with a 5 paid-license version of AVG Home 2011. It fails with the same symptoms on TWO computers. I won't attempt installation on any more until the issue is resolved because I lose the prior installation, leaving the machines unprotected.
AVG must know about this since I've seen this problem described by many people on several bulletin boards.
I had AVG 9.0 before I installed the 2011 edition. however, the 9.0 edition disappeared after I started installing 2011 edition. I also could not install 2011 edition. It showed me that it had error like this:
Error code: 0xC0070643
Error message:General internal error.
Additional MESSAGE: MSI Engine: Failed to install the product.
Context: AVG product installation
how can I fix this problem.could someone please help? Thank you so much.