What John said is true, either processor will handle Windows 2003 server
providing that all other factors are the same or nearly so.
Same amount of memory (1GB Ram should do, 512MB works), same hard drive
specs (Drive speed being the most important) and same Video Card. The low
end video card you mentioned might be a weak spot.
However the Celeron runs at 50% better than the clock speed of the Pentium
4, a P4 at the same speed as the Celeron would easily outperform the Celeron
at things like streaming video. But the P4 you mentioned is (assuming it
supports a 533Mhz FSB) and even with the 1MB cache may not handle the video
any better and maybe not as good as the faster Celeron.
I'm going to look at some benchmarks for these two processors and see what
if any advantage the P4 has (especially in Video) and will report back later
today if at all possible.
PS: If you know how to administer Windows XP Pro fairly well, then you have
the basics for 2003 server, both use NT based technology.
Jim