Hi all,
I want to get a video/graphics card for my pc so i can play games on it . Im not even sure if my computer is even capable of it. The motherboard is an AOpen s651m and has an agp4 slot on it, the cpu is a pentium 4 2.80GHz and 736 MB of ram. The os is xp home with sp2, any help is muchly appreciated.

Generally, any AGP 8X card will run in a 4X slot, but of course, just not at full potential - that said, it is not likely you would notice the difference, unless you could do a side-by-side comparison.

In your case, you only have 768Mb of RAM installed. The "sweet spot" for XP is generally considered to be 1Gb, for single core CPUs like yours.

Then, because you are using "on-board" or integrated graphics, your system has snatched 32Mb of system RAM and dedicated it to graphics, thus leaving you only 736Mb of RAM.

It would seem you either have 3 X 256Mb or you have 1 X 512Mb + 1 X 256Mb and that is certainly better than having 512Mb only, and then some stolen for graphics, but still, I would recommend you bump your RAM up to 1Gb first. That will get you the most "bang" for your money because XP loves RAM, and also because XP and the CPU will not have to spool data out to the Page File on the slow disk drive as often.

Then go for a graphics card.

Even the most budget cards will likely yield significant graphics performance improvements. This is because of many things that all combine to boost performance. The graphics processor on cards are generally faster than integrated in motherboards. Cards come with their own RAM that is "tweaked" for graphics processing. Previously dedicated system RAM is freed, in effect adding RAM.

You left out an all important fact - your budget. I recommend you look at Tom's Hardware Best Gaming Graphics Cards for the Money. Look under the AGP section.

There are a couple drawbacks to adding hardware to older systems. All too often, the power supplies that come with system are barely adequate for the original hardware. Start adding RAM, an extra drive, or a graphics card (which tend to be power hungry), and suddenly, your PSU chokes, or your computer starts behaving badly (often resulting in hard to troubleshoot problems because symptoms don't point directly to the power supply). Also, added hardware adds to the heat removal demands placed on the case.

So I would advise you pop the side of the case off and inspect the interior. Look at the RAM, note the number of modules (sticks) and see what you have for slots. According to your manual, you only have two slots, so it will be necessary to toss a 256Mb to make room for a second 512Mb. The cost of keeping current - I have a big box of old 256, 128, 64, and 32Mb RAM modules - and I'm about to add some 512Mb modules - - oh well.)

These popular RAM makers have auto-scanning and/or manual entry RAM wizards to help you determine compatible RAM. For manual entry, enter/select the PC or motherboard make and model number and the wizard will list compatible RAM.

Crucial - Memory Advisor
Corsair - Memory Configurator (manual data entry only)
Kingston - Memory Search (manual data entry only)

The following retailers have auto-scanners and manual wizards. They sell brand name and/or "house" brand (re-branded) RAM.

Newegg - Memory Configurator System Tool
MemoryStock - Upgrade Configurator
18004Memory - Configurator

Look at the label on the power supply and see if you can determine the wattage specifications. Use the eXtreme PSU Calculator Lite to determine your power supply unit (PSU) requirements. Plug in all the hardware you think you might have in 2 or 3 years (extra drives, bigger or 2nd video card, more RAM, etc.). Be sure to read and heed the notes at the bottom. I recommend you set Capacitor Aging to 30%, and if you participate in distributive computing projects (e.g. BOINC or Folding@Home), I recommend setting TDP to 100%. Research your video card and pay particular attention to the power supply requirements listed on your video card maker's website for your card. Then look for power supply brands listed under the "Good" column of PC Mechanic's PSU Reference List. Ensure the supplied amperage on the +12V rails of your chosen PSU meets the requirements of your video card. Don't try to save a few dollars by getting a cheap supply. Digital electronics, including CPUs, RAM, and today's advanced graphics cards, need clean, stable power. A good, well chosen supply will provide years of service and upgrade wiggle room. I strongly recommend you pick a supply with an efficiency rating equal to, or greater than 80%.

Check the case for additional or larger fan options. Often, in front of the drives, behind the front panel, you can add a fan. Or a larger fan can be mounted in place of current smaller fans. Any new fan will need power, so look for a free 12VDV connector - the same as plugs into EIDE drives.

While in there, make sure there is no heat trapping dust build up.