we offered to install Linux for free and find open source apps that a company would use instead of Windows ones. My partner was a Linux expert. No takers.

Then we offered Linux as a server with SAMBA and got a few takers as they saw that it saved them a bundle over NT Server and could be used on old hardware. Still had those who wanted to pay extra for an NT Server.

The bulk of our work was Windows technologies and the occasional DOS machine or two.

Trying to convince managers to use Linux over Windows is a very hard sell.