I would recommend learning Linux over anything Windows based. All the dudes I know who specialize in Linux all make 6 figures.
Gotta cosign this. Even if you fully support Linux boxes though you will undoubtedly touch Windows machines, so it's good to have some knowledge in administration of Windows servers. I've sort of dedicated myself into learning a language(Python). It's the one thing holding me back, I've got a good knowledge of various flavors of Linux(Debian-based, Red Hat-based), but my scripting skills hold me back. I would suggest everyone to do so, pick up a language to learn and a configuration management tool and deep dive(Puppet, Chef, Ansible, SaltStack). If you can get your skills to a professional level, you'll make money and be able to work wherever you want.
I did desktop support for 5 years before getting fed up with the low salaries and repetitive work. I ended up switching to a job as SQL Report writer in order to leave desktop support. That job was writing reports for a helpdesk that supported McAfee ePO security software. After constantly viewing ticket data for a year I was good enough to start supporting the software myself. So when a bunch of people left for other jobs they gave me a shot. And that's how I got started in IT security. If I had stayed in desktop support I would probably still be there. Most companies can hire experienced Windows Administrators pretty easily so why promote a desktop support person to that role?
I get calls from people I used to work with on the helpdesk who are still doing the same thing years later. What people don't tell you is with that many people having the same skill set it's damn near impossible to move up.
My story sounds similar. Desktop Support has a glass ceiling on it in many organizations.
VERY few internally promote people for the reasons you brought up. Level 1/2 support is a job that you're supposed to be at for a year or 18 months, get your feet wet and build your skillset, then take other roles. I feel bad for some of the dudes I worked with, been at the job 10 years, still doing the same damn thing they were doing when they started
The only Microsoft guy I know making that amount works with their CRM product. Windows administrators grow on trees and you can find one anywhere.
Sharepoint architechs get guap.