I use the Windows OS right now, and I have for a lot of years. However, there was a time (a couple years around the 1990 timeframe) when I actually succeeded in running my PC with zero Microsoft software.
I ran DR-DOS, Borland Quattro Pro, Lotus Word Pro, and a bunch of other quality (for the time) non-Microsoft software. I was happy about this.
Later, when I studied computer science in college, we used unix at school and it was at this time that I first loaded Linux on my home PC. I again made an effort to see how far away I could get from Microsoft products.