Making A Mess Setting Up Outlook 2007 With MS Exchange Connection

I have Avast anti virus running as my preferred AV software. To date I have not needed to use Outlook, but this year its usefulness increased as it saves me accessing work emails through my browser (as well as maintaining the calendar and stuff). So, I start the first run set up. All went well until it asked me to log on to the exchange server. When I did so it refused, eventually telling me I had to turn off the SSL(?). From what I could see, I could only do that after the address was entered into the profile, which it won't let me do. I did some digging and read (somewhere) that Avast was the problem. I tried temporarily disabling filters and logging on again, but no different. As a test, I fired up my laptop, also Windows 7, disabled the Avast filters, started Outlook for first use, set up the Exchange connection, logged on fine. Restarted the filters, all good! So next I try to reset Outlook to first run on my desktop. Can't do it. It resets Outlook to default, but doesn't bring up the set-up screen. I suppose I can uninstall Office all together (I'd only need to back up OneNote at this stage) and run a registry cleaner, but I'd rather not at this stage. I tried importing the registry settings from the laptop (no lectures please). This sort of worked; it now tries to log on to exchange on start up, but still fails. Something is still blocking the connection. Any ideas on what the block is?