My 7 year old is wanting to make computer games. Is there a good starter program that I can use to help him make video games?

Maybe start him off getting comfortable with simple programming:
programming languages for children - Google Search (http://www.google.ca/search?source=ig&hl=en&rlz=&=&q=programming+languages+for+children&btnG=Google+Search&meta=)

When I was a kid I made games with my friends using a program called qbasic. You won't be able to do anything really fancy, old mario style games after you get used to it, but you learn a lot about math early on and it was easy enough for my friends and I to do without reading a book. Here is a link to the program (even though I haven't downloaded it to make sure it's the actual program but I'm sure it is)
Qbasic - Free software downloads and reviews - CNET Download.com (http://www.download.com/Qbasic/3000-2069_4-10577955.html)