Game freezes, memory low

downloaded Mount and Blade, installed, started and get a popup saying I only have 475 mb of memory and the game needs 700mb to run. click okay and then goes to game menu screen, click start and it freezes. Any ideas?

vista64prem
asus m3a mother
amd 6400+
4 gig ram
4870 x2

Don't know why but solved it. Changed my page file to auto and run the game in a window. Now no problems.