Yeah textures can look completly different sometimes, depending on your graphics card.

You can increase the texture resolution (Not too sure where it is in the material attributes as I dont have my PC here with me but I think it migh be in display) set it too 256x256 (think thts right) and it should look better in the view screen, this can however slow your PC down so juat use it to check the positioning of the texture etc by using it with an IPR render.