I would like to build an editing pc for my nephew. He and his friends have been using a mini HD camera to make some pretty impressive (red corn syrup filled) little films, but he doesn't have a modern computer and it isn't really convenient for them to use mine all the time.
So I would like to build him one to take home.
Basically the computer would be used for Sony Vegas 9, which I can give him. I already have a power supply, case, and monitor I can salvage too. Unfortunately I am very limited on budget, about 400 is all I can spare. I would ask his father to pitch in, but my brother doesn't see a lot of value in this type of thing... Can it be done? I haven't built a computer since the mid-90s...
2 things: the CPU and the EULA. Video processing is done primarily on the CPU. Video decoding is done with the GPU though something like a GTX 460 for the video card and an i5-2500K for the processor might work for your needs. This processor is easily overclocked, but requires a P67 or Z68 motherboard in order to do it. Videos are monster-sized files so you'll need a big hard drive. I'd recommend at least 500 GB, 250 GB at the bare minimum.
As to the EULA part, remember that, unless you have a multi-computer license (or multiple single-computer licenses) for Sony Vegas 9, you cannot give it to your siblings unless you transfer your license (completely remove it from your computer and put it on the new one).
Building a computer nowadays is very easy. If you can match triangle-shaped pegs into triangle-shaped holes and the like, you can build a computer. Only the case's wiring is the exception as it's still possible to get positive (the colored wire) and negative mixed up.
What kind of PSU do you have? Does it have any PCI-express x16 connectors? If not, you'll need to use a lower end video card, like a 530 or something. The PSU must have the CPU +12V connector as well. Do take note of the amps on the +12V rail(s) on that PSU.
Edit: You must also have an operating system as well. You can't reuse any current OSs either, unless you have an extra license. OEM versions cannot be transferred at all.