Guillen is already under contract for next season with a team option for 2012, but there had been speculation he would leave to join another club.
"I'm very excited," Guillen said before Monday night's game against Boston. "I want to be a White Sox for the rest of my life."
"It was a very good conversation, a great conversation," he said.
Williams said it was a short meeting.
"I asked him directly did he wanted to be here and be the manager of the Chicago White Sox? He said, 'Absolutely,'" Williams said.
"He said he never asked for an extension," he said. "But he did want to know what his status was."
Guillen and the GM have clashed in the past, but Williams said all that is in past.
"The waters haven't been as smooth as in the past around here," Williams said. "(But) the man stands in front of you and says I understand what your concerns are, I understand what you expect and I'd like to move forward ... and wipe the slate clean."
Guillen guided the White Sox to the 2005 World Series championship. Chicago went into Monday night's game at 83-72, and has been eliminated from postseason contention.