Well you have more than enough stuff to run the game, but I don't know if any of the hardware isn't compatible with B&W or anything.
But are you on an administer account? It's never said access is denied for me when patching, but I run all my stuff on an admin account, so...
Edit: In response...
I gave up on building big cities (well, not GAVE UP, but don't do it much) because the landscape I'm stuck in is always tiny and sloped and stuff so building outwards gets hard ;;
Which is why mods are ftw
Normally I just play as good, because I can't seem to keep up having an evil creature in BW2 (since I don't want him slaughtering my own people in it)
But lately I've built up a big-ish city using nothing but skyscrapers for housing, have a ton of granaries/fields/farmers, then I turn half the...
Uh, they have editors, don't they?
You compile (or whatever the word for this is) an existing map into it. I don't remember what program, but I THINK it's in the downloads here.
(Then again, I haven't done it for a long time so I don't even remember if it works)
I don't think they eat in prison either, actually.
I had some people in a prison for a few years in a town with no food and they didn't die, so :( (don't ask why, I don't remember that part)
And actually, I wouldn't mind having a way to add new kinds of troops through modding... even though...
Didn't work in Paint and GIMP, but I got it to work by converting it to 8bit grayscale in GraphicsGale (I just forgot to reply, lol)
Not sure why it didn't work in Paint, though, as I've used that before for this (before I had any decent software :()
Does B&W have registry access? (it stores which symbol is yours in the registry.)
HKEY_CURRENT_USER\Software\Lionhead Studios Ltd\Black & White\LHMultiplayer\Profiles\(name here)\player symbol, if it helps
If you're on Vista, try running it as an administrator, though I have no idea how that...