It is hard not to have used Microsoft Windows, if one has worked in business environments. However, as Apple has migrated Macintosh to Intel chips, we see more professionals using that platform rather than just a PC. With the ability to dual boot either Windows or Mac, it gives the option to remain business office compatible, while taking advantage of better presentation capabilities, a more modern OS, and a system that is quicker, and less prone to problems. Keep an eye on Apple.
I still have a soft spot for the Amiga platform - the first true multimedia multitasking computer. It was 20 years ahead of its time, and brought broadcast quality multimedia to the home user. Newtek and their VideoToaster innovated the CGI industry in both television and film industries. My A4000T is still a viable machine, even though it runs at 25Mhz with 16megs of RAM, rather than systems today requiring 2Ghz and 2Gigs of RAM. An example of where simple and efficient design can stand the tests of time. Sadly, Commodore failed as a going concern, and there have been some attempts to revive the concept. Funny how in its inception, business believed there was no need for multimedia nor multitasking capacities. Look at where we are now. A project is underway to relaunch the Amiga concept under a new generation of technology - the X1000 from A-Eon.
Networking systems, whether for office or home, are a knowledge base for me as well. I have configured my own home network, and like the ability to print and access information from anywhere. Today, it is even easier with most homes now using firewall routers and wireless connections to configure the home for work or entertainment.