Hello sirs, I have such trouble in one PC, I installed clean installation on PC, i formated a C: drive and after installed Windows 7 ultimate 64bit on it, PC is with dual processor and 4 GB RAM, installation finished normally, i installed all manufacturer drivers on it, PC is new bought and i had own CD disks for installation of all drivers. But the problem is that PC works very slowly, when desktop appears it is thinking a long time, speed is not good. what can be reason of it? if anyone can please help me. thanks in advanced.