Hey, i know how it feels. I have been there more times then i ever wanted. It really sucks when you cant afford new or the latest hardware just to be sure you can play a game.
Extreme Graphics 3D is probably built into your PC. Its a sort of graphicscard, but it wont have the same preformance as a "loose" one. But your PC seams to be relative new, so it just might work.
The card on the picture is a S3 64Mb, cant remember the maker of those cards (Virage???). My brother had a 32Mb version in his old PC. You do need to open up the computer to install or remove a graphicscard. They usally sit in the AGP or PCI slot, you
cant put it in the wrong one.
When buying a card, you get a CD with the correct drivers on. You uninstall the old drivers. Turn the PC off. Make sure the powercabel is unplugged. Then it is just opening up the side, remove one screw and then it is just pulling the card out slowly. Attach the new card on its right place (AGP or PCI). Screw it all together. Start the PC up again, you can put the CD with the drivers in the CD-rom or DVD-drive. You PC will search for the new cards driver and install them. Then you make the last settings by right-clicking on the desktop. Choose "properties", then "settings". Make the changes that suits you and finito.
Lock On: MC-specs.Windows(r)98/ME/XP/2000
Pentium III 800/AMD Athlon 600 or better
256 MB RAM
(512 MB RAM recommended)3D video card (DirectX 8.1 compatible) w/32MB RAM
(128MB recommended)Sound Card (Direct 8.1 compatible)
DirectX 8.1 or higher (included on disc)
4X CD-ROM or better (Not recommended for use with CD-RWs)
(Internet connection (56 kbps or better) or LAN for multiplayer)
Hard Drive Space 1.1 GB
I suggest a 128Mb or 256Mb AGP-graphicscard of whatever brand you can afford. Most cards today are of high quality even the cheaper ones. Btw make sure you have an AGP-slot on your motherboard first, (grey rectangular slot). These work faster on older machines. The AGP can send and recive more information faster then the PCI-slot.
You defenatly need more RAM, Lock On: MC recomends atleast 512 RAM. I can almost bet that your PC is working a bit slow now. But i recomend this because of what i have heard and been taught, that Win XP needs a minimum of 1Gb RAM to work optimal. Anyway im working from my point of view, meaning what i would of done if i had your hardware and wanted to play Lock On: Modern Combat.
Just out of curiosity, what speed does your CPU have?
If I dont have a graphics card and I still try to install it it will probably crash my computer and it will need rebooted right? It will probably crash once you try to start the game or it wont even let you start it. But nothing will happen during the installation.
Hope i did not forget anything...