Conversation so far:
what is BASIC?
programming language.
when did he develop BASIC?
After Gates read the January 1975 issue of Popular Electronics, which demonstrated the Altair 8800.
was he able to secure a job because of inventing BASIC?
Gates took a leave of absence from Harvard to work with Allen at MITS in Albuquerque in November 1975.
did he further develop BASIC?
Microsoft became independent of MITS in late 1976, and it continued to develop programming language software for various systems.
was he able to pitch BASIC to people or companies?
Microsoft's Altair BASIC was popular with computer hobbyists, but Gates discovered that a pre-market copy had leaked into the community and was being widely copied and distributed.
What did Bill Gates finally do with BASIC?
Gates wrote an Open Letter to Hobbyists in the MITS newsletter.

Question: once he got rid of BASIC what did Bill do?
Self-contained rewrite: Once Bill Gates got rid of BASIC what did he do?