He stole computer time at the local college, and dumpster-dove for source code to the BASIC others there were working on. He admitted as such decades ago, now he's trying to whitewash/rewrite history.
He bought MS-DOS from another dev in the area, relabelled it and then sold it to IBM via a contact he got into IBM's management via his mother's social circle.
He had the arrogance and nerve to shame members of the Homebrew Computer Club for sharing code for free amongst themselves, stating that he thought software should all be for-profit and proprietary.
F*ck Bill Gates, never forget his true colours. He can afford to sound gracious in his old age and ill-gotten wealth, now that he no longer needs to do, well, anything.