First DOS/PC experience at the Technion, Israel's Institute of Technology, back in 1988. Was a heavy Apple 2c (or 3c) user in the early 80's.
First job in the early 90's: Turbo Pascal under DOS (with some Assembly as well). When Windows 3.1 was released and Visual Basic and its VBXs came around I never really wanted to look back.
Unfortunately had to go back to the 60's at one point in my career and write C++ code under Solaris. Yuck.
I'm happily back now and could not think of not using the .Net Framework, Visual Studio, SQL Server, etc... to design and implement my apps.