Came across an odd problem today – the PC was able to access normal websites, but not https secure sites?     The user reported having problems with an uninstall of Norton (they were now using AVG).   After a bit of hunting on google, I found that this was indeed due to an incomplete uninstall of Norton (in this case Norton 360 – however problems with other versions were reported too).

The solution?   Symantec provide a free tool for cleanly uninstalling their AV tools:

http://service1.symantec.com/Support/tsgeninfo.nsf/docid/2005033108162039

After running the tool, the problem with https sites was resolved!