It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

×
I've been thru the first ten (10) pages of this thread and have yet to find a workable solution for upgrading the 4:3 resolution to widescreen. (BTW My PC's res is 1280x1050 .)
You can try what was posted in this topic:

http://www.gog.com/forum/dungeon_keeper_series/cant_get_a_resolution_higher_than_640480

I have no idea if it will work for you.