I am running an older but very stable and serviceable machine that up until now has handled everything thrown at it. Older machine with XP, 3gig processor, 2G Ram and a 256mb Video card. When running a very complex house design using an architectural program, it works great until I do 3D rendering. Slows down to say the least and often crashes. It is old enough that it won't take a PCIe card and so I can't upgrade to a higher end graphics card (I don't think). I upgraded memory some time back to 2 gig and upgraded the power supply when I added the new video card. I really don't want to go to a new computer but am at a loss as to how I can soup this up any further. Any and all thoughts appreciated.....I am a user not a geek so keeping things on the dumb level would help me here.....