I am currently running Windows 7 Ultimate (upgraded from Windows Vista) on a Dell XPS420. I was having problems with no sound. Everything shows my sound is working properly. Upon looking further I found under devices the following: Microsoft 6to4 Adapter (code 10) ISATAP Adapter, #2,#3 and #4 all have issues as well as Pseudo-Interface All state none can start....What are these and do I need them? Thanks

An error code 10 is usually a driver issue. It’s described here http://support.microsoft.com/kb/943104