I can absolutely explain why, but the short answer is that the components you chose are extremely outdated, the cpu is too low for entry level gaming imo and just about the same can be said about the video card
Here is the longer explanation:
if you system doesnt blow up from that crap psu then good luck, I understand your on a tight budget but you gotta do better then a 12 dollar logsys that likely doesnt deliver anywhere near the specs its supposed to and it will degrade your components if they are not being properly fed power, thats right you can easily age your system with a crap psu. You have selected a prebuilt comp with a p4, not even a lowly dual core your system will be severly held back from that as it is, then you have, not to mention that that video card is terrible and extremely outdated, you will get very very low performance overall in most games if they even run at all, save a little more money and ebay some am3 parts at least for low end gaming. Give me your budget and I can piece something together.
You could get a budget gaming rig on ebay for 2-300 dollars with everything you would need, thats what id be on the lookout for given your strict budget requirements.
I saw a desktop with a e8400 and a gtx 260, 4 GB ddr2 go for 180 plus 20 shipping the other day, you should keep your eye opened, I usually search "gaming rig" or "gaming computer" or "gaming pc"... good luck