what card do you have...? some people have been having problems with certain components, while others with the same components are not having any problems at all, it seems to be pretty random...
I had to install 4 times for my 4850 driver to work, I tried 3 times and it wasn't functioning properly, I then reflashed my gpu back to stock and on the next install the drivers worked, weird, maybe it was just a coincidence...
I also had a SM Bus problem, so after the 2nd, 3rd and 4th installs, the first thing I did was go to my setup folder on one of my storage drives and install my chipset drivers...