They're right, you need to optimize your PC.
Though, side note (for you); if you're not familiar with PC optimizing it's likely that you're not familiar with PC security. I would suggest taking measures to secure your PC especially if you're downloading game software from torrent sites which may not be coming from a reliable source.
There's a few shareware programs you can use for PC security: AVG, Spybot S&D, CC Cleaner (be sure to enable secure deletion with at least 1 pass), Smart Defrag, and lastly for extra protection; ThreatFire -- it can run alongside your AV detecting signatures and malicious activity that isn't picked up by your AV, which gives you extra protection. It'd be good in your case if you plan on playing games downloaded from torrent sites.
HF.