The identity of the investors remains a mystery, but according to reports, the three are lobbying Microsoft's board of directors for Gates to be replaced.
The investors collectively own 5 percent of the $277 billion company and have been adamant in their demand that Gates be replaced, especially now that CEO Steve Ballmer has announced he will retire within a year.
According to Sky News, in spite being one of the world's most valuable technology companies, Microsoft's shares have remained fairly static over the past 10 years as the company has struggled to keep up with ever growing competitors Apple and Google.
Gates, 57, has been increasingly lowering his profile at Microsoft and currently owns 4.5 percent of the company (from 49 percent in 1986).
Notable deaths of 2014 [PHOTOS]