Do you own the Toshiba Satellite C855D-S5320 laptop?  Do you hate Windows 8?  Want to install Windows 7 in its place?

I struggled for 10 hours to help my brother do just this and these few steps will save you a lot of googling, waiting, and from pulling your hair out.

  1. Go into the BIOS (by hitting F2 on boot) and make your CD the 1st boot device (it’s called ‘ODD’ under the ‘Boot’ menu).
  2. While in the BIOS, also change the ‘Boot Mode’ under Advanced > System Configuration from ‘UEFI Boot’ to ‘CSM Boot’.  Windows 7 requires CSM to boot from the Windows 7 CD/DVD and Windows 8 requires UEFI.  You may also need to disable ‘Fast Boot’ in the BIOS to be able to boot off the Win7 DVD.
  3. After installing Windows 7, open up Device Manager and you’ll notice a warning message next to 4 items.
    • Network Controller
    • SM Bus Controller
    • Universal Serial Bus (USB) Controller
    • USB2.0-CRW
  4. Don’t waste your time searching on Windows Update for these drivers, it does no good.
  5. Download this zip file and the tc50124300j.exe file  (it’s a Windows 8 driver but it still works)  [Also available here on, the zip file and the tc50124300j.exe.]  It includes the drivers to fix these errors and enable WiFi, the USB card reader, USB 3.0 suppor, and give you AMD’s Catalyst drivers.  The .exe file will fix the SM Bus Controller error.
  6. For the SM Bus Controller in Device Manager, right click on the ‘SM Bus Controller’ and choose Properties, then Update Driver.  Then Browse to where you extracted the tc50124300j.exe file  ‘…AMD Display Driver > Packages > Drivers > SBDrv > SMBus > W764A > SMBUSamd.inf ‘.  I believe I only have the SMBUS.amd.inf file in my .zip file and you need the driver itself not just the .inf file to install it.  That should do it.
  7. For the remainder of the devices in Device Manager, unzip my zip file and run the Setup file in each folder and afterwards run the amddriverdownloader.exe. (you can ignore the ‘t12 sm bus controller’ folder in my zip file because it only contains the SMBUSamd.inf and not the driver itself, my bad)