Warband isn't a demanding game hardware wise.
At leash 8 gigs RAM & an intel cpu, say 3.2 ghz is plenty good for NW.
Gfx card? An older Nvidia card is fine ..., bet the game would run on a newish onboard intel motherboard chip.
My pc is old. 3.4 ghz cpu, but throttled, WB only draws 2.4 ghz under load.
Plus, use an old 450 Nvidia card which might strain at high resolution, 1600X900, but is fine at lower rez.
Hope that helps.