I'm trying to normally install web parts, e.g. RSS feed reader from
Smilinggoat and Gant Chart web part from Teun Duynstee, but with I keep
getting "The specified server instance not found. Please specify the
server's address and port" error message. I tried using stsadm with RSS feed
reader instalaltion and .MSI package with the Gant Chart web part, no luck
with either one.

Any idea how web parts are installed in an WSS 2.0 extranet environment
using SSL and Certificates? System was set up by my predecessor, and of
course there is no documentation what so ever about the installation and
configuration.