a display only really works one way, the PC send the signal to the monitor. it might be the fact that your graphics card is integrated meaning its actually on the motherboard as apposed to a interchangeable unit.
as for getting a new video card that might in turn force you to upgrade the motherboard, cpu and ram. you might as well just get a new PC. 5 year old computers dont really transition well with current technology. you might be able to find a card that fits the old motherboard if we knew what it was. But if you have something like a dell/hp it might not be possible to upgrade.
I would suggest getting a new setup. And this time build it yourself, it's actually really easy. I built my first PC 6-7 years ago and it was half the price and it didnt come loaded with a tonne of useless software i didnt use. don't buy a "namebrand" box off the shelf.
it wont cost as much because you can reuse some of the parts from your current PC like monitor, mouse, keyboard, dvd-drive, powersupply(possiblly) and hard drive. the only things you will need to buy are the case, motherboard, CPU, video card and ram and of course a new copy of windows if you need it. I have had the same case, powersupply, dvd-drive for years
