Side-by-side configuration is incorrect?

[Bob-Tuba]

I'm pretty sure I updated the Avast! Free from 8 to 9 and now I can't get to it.

The error message I get is:

>>
C:\Program Files\AVAST Software\Avast\AvastUI.exe

The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace.exe tool for more detail.
<<

The Action Center (in my system tray) is now warning me that I'd better, "Find an antivirus program online (Important)".

Bob

[Bob-Tuba]

I have Windows 7, 64-bit.

I've been having problems with unreadable blocks on my hard drive.

[Bob-Tuba]

I have Spybot S&D and the firewall that comes with Windows.

[Bob-Tuba]

It was the program update.