Port already in use during installation

Hello all,

I’m trying to install wM 4.6 on Win 2K using webMethods Installer 4.6.1, but during the Enterprise Server Configuration, i’ve got the following error :
“Choosing a base Server port of 6849 also reserves ports 6848 and 6847. One or more of these ports is already in use or cannot be bound. Please choose a different Server port”

However those ports are not in used nor 7849 (checked with netstat) and no other webMethods products is installed (I’ve cleaned it up).

The only reference I’ve got on my Windows machine about those ports are in the registry :
which unfortunatly I could not remove.

So, are you aware of any solution to bypass this ?

Thanks in advance,