My specialties are the registry and file system.
I never had any experience with computers until 1995 (age 39!) I was totally amazed and began experimenting immediately.
I was the Windows guy in the IT department at a library, where its my job to keep patrons from changing settings and out of the file system on over 100 PC's at 7 locations. (Yes, I have job security)
I provided 2nd tier support for PCTools software based in Australia for over 1 and a half years