|"Motherboard: MSI GF615M-P33"|
Did you choose the board or did you buy a kit? It's a cheapie based on the old nForce4 chipset which was originally designed for the S939 A64.
"GPU: ATI radeon HD 4600"
4600 is the series...which card do you have, HD 4650 or HD 4670? The 4670 is considerably better.
Check your CPU temp to make sure it's not overheating. If you don't have a hardware monitoring program installed, MSI *should* have something available. If not, try HWMonitor:
If overheating isn't the problem, boot into safe mode & run a full virus & malware scan. You should also download & install CCleaner-slim & use it regularly:
If you don't have an anti-malware program, try MalwareBytes: