SEO is a farce. I have to agree with metguru. Just out of curiousity, I just put
0x800106ba
into google, and the very first result is the microsoft help and support site (which, btw, the error that the OP posted says to check), which tells you how to fix the problem.

But hey, since a lot of people don't know about the microsoft knowledge base...
http://support.microsoft.com/kb/
Just put you error code in the search box that pops up.

Avira is probably one of the best free AV programs out there, but I would like to point out that Windows Defender and Avira are not the same thing. Windows Defender is not an AV program. It is techinally an Anti-Spyware program. The free version of Avira doesn't include spyware detection. Microsoft has Defender, Malicious Software Removal Tool, Security Essentials, and Forefront Client Security.

Believe it or not, Microsoft Security Essentials is just as good as any other "full featured" free AV program (ie, does spware, adware, trojans, worms, and virii).