I'm not an expert and have only gleaned some information from friends who work in the field.
Anyway, your current computer uses an integrated graphics card. This means it is competing for access to your computer's RAM. While these cards are more useful and powerful for less intensive graphics processing, it leaves something to be desired at more graphically intensive games. I don't know the specific make and model of your card, so I can only guess, but included below is a brief comparison between a Intel HD graphics card and the minimum recommended by SE.
http://www.game-debate.com/gpu/index...force-gtx-660m
Although the example is ridiculously overpowered to begin with, you should pay especial attention to the GPU display specs. The GPU memory information is less useful unless you are doing work in the CG and SFX industry, at which point you should know all of this already.
There are two ways to find your computer information:
1) Go to "Control Panel", click "Hardware", and find your "Device Manager". You can find your specific graphic card that way. Its type should be labeled as "display adapters".
2) Open your "Start Menu" and click the following: Programs -> Accessories -> System Tools -> System Information. This should give you an easy printout if you want to ask for specific suggestions and advice from an expert.
You may post here, but it is probably better to simply have that information prepared and try finding help on a technical or pc building forum. Of course, feel free to omit any information you feel is too personal or sensitive.
Also, I would not suggest poking around the computer yourself without extensive preparation and research. Dell PCs are notoriously tricky and difficult to maintain and change. This is even more so since your system is an all-in-one, which means the pieces may be customized to fit within the frame or use specialized software drivers. So it is as Apinaheebo said, it is not going to be a cheap or fast fix to change anything on that PC.
BTW, your RAM and CPU should be fine. The graphics card is your biggest hurdle at the moment. It is just complicated for this computer by the fact you have to find a card that not only meets the game requirements, but has to fit within the frame, meets the power limit of your power source, meets your cooling requirements, and won't cause any catastrophic driver errors. If you're still determined to give it a try, most of your hardware specs should be online, printed on the computer box, or printed in your computer.