Boot Camp 5.1 for Windows 7 driver setup file missing
I am not sure if I am only one here. I have Windows 7 Ultimate 64-bits, and I just followed Apple instruction on Boot Camp 5.1 and got all the files for drivers on USB (came with 16gb, 3.0) and it was setting up smoothly till boot into Windows 7 setup on macbook pro, and then it says can't find drivers, so I manually open folders in this USB and it show files list, and I also opened the file that I downloaded from Apple (Boot Camp Support Software 5.1.5621) then plug in Windows on mac, and they picked up the USB and all those files, however I don't see any "setup.exe" anywhere. Is there missing file or something?
Thanks for your help in advance.
MacBook Pro with Retina display, OS X Yosemite (10.10.1)