Side by side configuration is invalid

Hello,

I’ve just downloaded Avast free trial after falling out of love with Norton IS.

Windows Security tells me that Avast is running but when i double click on Avast I am told that it cannot be opened because the side by side configuration is invalid.

Is there any way to fix this?

My laptop runs on Windows Vista and I uninstalled Norton before installing Avast.

Thanks!
Jenn

This is most commonly associated with:
Side-By-Side Configuration is Incorrect Error - You need to install MS Visual C++ 2008 Redistributable.

You need 2008 SP1 - this is the one:
Microsoft Visual C++ 2008 SP1 Redistributable Package ATL Security Update
Note this link there are 64bit versions there (IA64, x64) ensure you get the correct one for your OS (x86 32bit OS, x64 64bit OS)

However that said I would also suggest running the Norton removal too to ensure everything is removed.