cannot start child processes?

I'm guessing this has been posted before, but since i'm new to the
group, here it is again. When I try to run a cgi-script I get and
internal server error and the following
error in my error_log:
"couldn't spawn child process:"

This is running on a windows XP Pro machine with a ton(1GB) or ram. I
cant see how the process table would be full, and I dont think there are
any more permissions
to set....so what is going on? How can this be remedied? Install Linux?
No that's
too easy.....

Jake