well, if my memory serves me right....
Bill Gates started Microsoft in 1975, he and another guy wrote a BASIC interpreter. Later IBM hired Microsoft to build DOS (then called IBM DOS, and later MS DOS). So windows was written in BASIC and DOS.
http://www.vbtutor.net/vbtutor.html
i suggest you learn C++ and /or JAVA.
join
www.builder.com
if you wanna learn the language, stay away from IDEs at first.
hope this helped.