its like this; in the options menu, where you select your WADS, you can choose any amount. you will start to see some odd erros if oyu go over 8 WADS in your settings, so if you have custom wads there, you should think about merging them i.e taking the textures from 1 wad and putting them in another. another problem is that you must have all your wads in your MOD DIRECTORY. i.e if i was making a half life map i would put all the wads i needed into half-life/valve, whereas with counter strike i would put them in half-life/cstrike. once you have chosen your wads in the options menu, the compiler tells half life to look for those wads in its mod directory, no matter where they are when you link to them in hammer. if they are not in the mod directory, then half life will give that error "could not load <wadname>". this happens even if you didnt use any textuers from that wad. to stop this happening, either move the wad in question to your mod directory, or remove the wad from the hammer wad list. if you remove the wad, you must close hammer and open it again because it will still be reading the textures from the wad.