I have had my PC for about 9months (my uncles old one) and whenever I play a steam game (CS:GO, DayZ, ArmA III, etc), it cuts out after about 15-20mins. I am not too sure if the Thermal Compound is alright, its been on there for about 4 years. Pc specs are as follows;
AMD Phenom X4 9650 64bit Quad Core.
6GB DDR2 333MHz RAM
ATI Radeon HD 4550
MSI 7501 Mobo