Microsoft directly profited from the conflicts and genocides across Africa in the '90s. This includes the Rwandan Genocide, Sierra Leone Civil War, 1st. and 2nd. Congolese wars, and the Somalian Civil War. All of these were scrambles for materials used in computers (such as gold, cobalt, and tin).

The leadership at Microsoft, including Bill Gates, knew their products were using unethically sourced materials used to fund warlords and terrorist groups, but looked the other way because it was cheaper. These materials were often mined by child and slave labor.

Quick overview of the problem as it has continued, despite Microsoft releasing annual conflict mineral reports each year since 2019:

https://www.gamesindustry.biz/microsofts-concerning-conflict-minerals-disclosure-reflects-industry-wide-slippage