Let's see if I can throw something else out there to help you
Download the attached file (drivers.zip)
Extract directory to your preferred location, I extract to desktop
Open up your computer's DEVICE MANAGER
Put the battery back in your phone
Initiate download mode on your phone (vol down + camera + talk/power)
Plug USB into your phone then into your computer while in download mode
Watch your DEVICE MANAGER to see if you notice any activity
Also, make sure to watch your system tray next to the clock if you see the driver is attempting to install using Windows Update double click on the icon with animation and then select DON'T USE WINDOWS UPDATE TO INSTALL DRIVER (something along that line)
Hopefully you'll see OTHER DEVICES appear if you do, click on the +
After expanding the tree you should see M900
Right click M900 and UPDATE DRIVER SOFTWARE
Since you're using Win 7 select BROWSE MY COMPUTER FOR DRIVER SOFTWARE
Browse to where you extracted the drivers
Click OK once you get the driver directory
Click NEXT
Hopefully this will initiate a window informing you that Windows cannot verify the publisher of the software
Select INSTALL THIS DRIVER SOFTWARE ANYWAY
Let the installation take place, might be quick or take some time
Continue to watch DEVICE MANAGER and the above steps until all hardware drivers (2) are installed (Samsung CDMA Modem and Samsung USB Composite Device)
Now you have the proper drivers installed, unplug the USB from your computer remembering which port you just installed the drivers on
Start the Sprint Utility and follow the instructions, when prompted to plug your phone into the USB port, use the port you just readied..
I hope this will get you going in the right direction. I'm unsure why you're having so many problems with this otherwise simple procedure
If all else fails, you can try a system restore to the latest date you can remember not having ANY Samsung software installed on
Man that looks like a personalized HOW TO just for you
