why does windows make it so difficultm to get drivers?

this has happened not only to me but other friends. I had bought a new 1.5 tarrabite HD, I went to a computer repair place and they wanted 150 to put a OS in my computer and install a new one. SO I bought and
put xp in my HPdc7600business computer. the OS did not reconize several drivers, I dopn’t expect microsoft to provide every driver for every diffrent component in every computer,BUT they should make it much eassier to find them, HELP ME PLEASE I cannot find the video controller (VGA compadable) or the ethernet Controller, my freind has a ibm and can not find the SM bus controller or her Video Controller also I am going to my a mac!!!!!!!!!~!
markymark