I had installed a CTP version of SQL2005 on my notebook, followed by the RTM... alongside a SQL2000 installation. Somewhere along the line, I could not longer connect to my SQL2000 installation (was it the SQL2005 installs? Can't say for sure). The error I got was:
SSL Security error :ConnectionOpen (SECDoClientHandshake())
So after poking around, I found this article, which descries the bug and leads you through deleting your certificates. It worked great, except in my case the Certificate was under "Current User" so note that the steps in the fix lead you through "local computer"
INFO AND CODE