What can I upgrade on my PC to make it run faster/lag less while gaming?

You can always get a higher wattage power supply to replace your 300W. I would say get more memory and a better graphics card with more on board memory too. Also, clean up junk files on your computer, clean your registry up with registry cleaning software, check for malware and viruses too. Another thing you can do is to go into the task manager and shut down any unnecessary processes. @Sookie, If done properly registry cleaning is good for your computer. Just don't use some random software, get something trustworthy. Oh, and Blue Screen of Death doesn't exist anymore unless your computer is very out of date.

Go to this website and download the program and use it: http://www.systweak.com/registrycleaner/softonic/?utm_source=softonic&utm_campaign=englobal It's free!