Rotating electric machine of the type comprising a housing (1a, 1b) that houses an active core with a rotor and a stator, the rotor being mounted on a shaft, wherein the machine comprises a rolling bearing retaining ring fasting system comprising: a rolling bearing retaining ring comprising a body portion with a hole for the passage of the electric machine shaft; the body portion comprising at least one guiding engaging means and at least one pressure engaging means; and a retaining ring receiving portion formed at one end of the housing, the retaining ring receiving portion comprising at least one guiding engaging means configured to receive the corresponding guiding engaging means of the rolling bearing retaining ring and at least one pressure engaging means configured to cooperate with the corresponding pressure engaging means of the rolling bearing retaining ring; wherein the body of the rolling bearing retaining ring comprises a rear surface, and the at least one guiding engaging means comprises at least one elongated projection protruding from the rear surface of the body and creating a spacing between the at least one elongated projection and the rear surface of the body; the at least one guiding engaging means of the retaining ring receiving portion comprises an elongated opening formed in a wall of the retaining ring receiving portion, the elongated opening being configured to receive the elongated projection of the rolling bearing retaining ring; the body is a circular body, the elongated projection extends in a curve partially following a circumference of the circular body, and the elongated opening is a curved elongated opening; the at least one pressure engaging means of the rolling bearing retaining ring comprises a protruding tab on the outer circumference of the circular body, and the pressure engaging means of the retaining ring receiving portion of the housing comprises a shoulder cooperating with the protruding tab; and the rolling bearing retaining ring has four spaced apart elongated projections and the retaining ring receiving portion of the housing. comprises four corresponding elongated openings. wherein the retaining ring receiving portion of the housing comprises a first circular surface formed on an edge of a shaft passage hole of the machine and a second circular surface formed adjacent the first circular surface and forming a step with the first circular surface, and wherein the elongated openings are formed on the first circular surface and the shoulder is formed on the second circular surface. a rolling bearing retaining ring comprising a body portion with a hole for the passage of the electric machine shaft; the body portion comprising at least one guiding engaging means and at least one pressure engaging means; and a retaining ring receiving portion formed at one end of the housing, the retaining ring receiving portion comprising at least one guiding engaging means configured to receive the corresponding guiding engaging means of the rolling bearing retaining ring and at least one pressure engaging means configured to cooperate with the corresponding pressure engaging means of the rolling bearing retaining ring; wherein the body of the rolling bearing retaining ring comprises a rear surface, and the at least one guiding engaging means comprises at least one elongated projection protruding from the rear surface of the body and creating a spacing between the at least one elongated projection and the rear surface of the body; the at least one guiding engaging means of the retaining ring receiving portion comprises an elongated opening formed in a wall of the retaining ring receiving portion, the elongated opening being configured to receive the elongated projection of the rolling bearing retaining ring; the body is a circular body, the elongated projection extends in a curve partially following a circumference of the circular body, and the elongated opening is a curved elongated opening; the at least one pressure engaging means of the rolling bearing retaining ring comprises a protruding tab on the outer circumference of the circular body, and the pressure engaging means of the retaining ring receiving portion of the housing comprises a shoulder cooperating with the protruding tab; and the rolling bearing retaining ring has four spaced apart elongated projections and the retaining ring receiving portion of the housing. comprises four corresponding elongated openings. wherein the retaining ring receiving portion of the housing comprises a first circular surface formed on an edge of a shaft passage hole of the machine and a second circular surface formed adjacent the first circular surface and forming a step with the first circular surface, and wherein the elongated openings are formed on the first circular surface and the shoulder is formed on the second circular surface.