Best ways to test hardware?

Well.. i wanna know what are the best ways to test hardware... HDD, ram, motherboards... if you are in shop and people drops computer at you to see if any works... what would be the best way to test all the parts of each computer and safe time

 

http://www.ultimatebootcd.com/

 

perfect i will burn that right away.... and will that work with power supplies too?...

and what i can use if i dont have time to conect each pc..

 

Power supplies can only be diagnosed with a multimeter. And there are NO servicable arts in them as there is a significant risk of shock. If you suspect a faulty power supply pull it and put a spare in. If the problem goes away then, chuck the faulty supply.