Url: http://support.microsoft.com/kb/890015

I am working in a Window Communication Foundation (WCF) project and I am trying to prototype using SSL for my service calls.  I am also working on Vista so I wanted to try out the new Client Signed Certificate feature in IIS7 that Scott Guthrie blogged about a bit ago.  I followed the instructions on his blog to the letter with no result.

The error I got when trying to start my site was “The process cannot access the file because it is being used by another process.”  The file was actually the 443 socket, not a file so this error led me astray for a bit until I found this interesting knowledge base article from Microsoft. It essentially walked me to through finding out who was listening on 443…it turned out to be Skype. Whooa… Killing Skype allowed me to start my SSL site locally.  I think I’ll just use an alternate port number for now to get around the problem, but at least I know what is happening now.

Whew…