|"The low end voltage in the BIOS is showing 3.7 and flashing red"|
What is the low end voltage? There should be listings for +3.3v, +5v, +12v, the CMOS battery (3v), & possibly others. The safe tolerance is 5% +/- so the limits for the +3.3v rail are 3.135v - 3.465v. Obviously 3.7v is outside the tolerance range so there may be a problem with the PSU.
"Its causing my CPU to overheat and switch off when i try to play games"
The CPU (actually the A8 is an APU) gets its power from the +12v rail so it's unlikely the +3.3v is causing the APU to overheat. If it is overheating, the problem probably has to do with the heatsink/fan installation. What is the APU temperature?