avast scan freezes at D:\Windows\System32\config. why?

I am trying to fix my computer, but when I scan it, Avast freezes up at D:\Windows\System32\config and I am wondering why. Also, i can’t update anything, it says there is an error. It’s on my Windows Defender, and Update. Any help would be great.

Strange as this may seem what is your firewall (Zone Alarm perhaps) ?

It is Windows Defender for Windows Vista or Windows firewall…

Windows Defender isn’t a firewall so it is the Vista firewall, which doesn’t exhibit the same issue of Zone Alarm that can cause this type of thing.

Have you enabled the Vista Firewalls outbound protection ?
If you don’t know then it probably isn’t enabled, as it is off by default.

What is the error when updating ?

If you are getting the same thing when trying to update windows defender, it could be malware blocking security based sites.
– HOSTS FILE - See this for a more detailed explanation on the HOSTS file, http://en.wikipedia.org/wiki/Hosts_file

Have (or did) you another AV installed in this system, if so what was it and how did you get rid of it ?