My dad used to work for Microsoft. 
Did he work at headquarters? It is located in Redmond, Washington.
Yes he did.
Microsoft was founded on April 4, 1975 by Paul Allen and Bill Gates. I'd say it's a fairly new company.
Yes it is fairly new still and a great success.
It got most popular starting in the mid-1980s because of MS-DOS, and then Microsoft Windows.
My dad started working for them in 1978.
Wow! Did he become a millionaire? The company has produced over 12k millionaires which is mind-blowing.