It looks like as long as you have DirectX 9.0, you should be able to play the game. Windows 7 comes with a more recent version of DirectX (DirectX 11) so you may see an error such as this: "The program can't start because d3dx9_35.dll is missing from your computer. Try reinstalling the program to fix this problem." If you do see this error, simply reinstalling the game should fix the problem. More on DirectX here, http://windows.microsoft.com/en-us/windows7/products/fe...
You're going to need some sort of video card whether you want to play a game or not. Without a video card, you won't be able to even log into Windows!
Exactly what video card do you currently have in your system? I'm assuming you have an integrated video card with your motherboard and that's what you meant rather than getting a dedicated video card.
Depending on the make and model of the integrated video card, you may or may not be able to play it. Most integrated video cards are terrible when it comes to game playing because they do not have the proper hardware to do any kind of major acceleration in 3D. So, depending on the GPU you currently have in your system, you may or may not be able to play it. I'm leaning towards not being able to play it unless you turn down all details and possibly play at the lowest resolution possible.