I have a Sharp printer/copier (MX3501N connected wirelessly) whose driver will not completely download from Sharpusa.com as it says I have an unsupported operating system. Windows 7 64 bit is what we have are running, I downloaded the driver for the 64bit Windows 7 and Windows 7 is supported by Sharp for this printer.
Thanks, I had tried that first and it didn't work for some reason. I then went to the Sharp website to download the driver and it was there that is where I received the unsupported OS message.
What ended up solving the problem was creating a directory off the root, loading the driver there, unzipping it and then copying over to where it needed to go. I also had to configure the driver with a passcode to print in auto configure.
This masterful solution came to me by way of Patrick of our local Sharp support group, (after 2.5 tedious and fruitless hours on the phone with my "local" Dell support personnel in India). However, Patrick still couldn't tell me why the invalid OS system message came up (repeatedly), nor why my CPU needed a password when other machines on the network don't; but it worked and that's the bottom line. I can print like a crazy counterfeiter, now. Happy girl am I.