The terms I remember (note that there are so many different Microsoft licensing agreements, so yours could’ve been totally different) were that you weren’t char

The terms I remember (note that there are so many different Microsoft licensing agreements, so yours could’ve been totally different) were that you weren’t charged if the problem you called for was indeed a problem with Microsoft software. And that definition was quite liberal: not just obvious software bugs, but also confusing documentation, etc. In other words, as long as you RTFM before you called, it was free.