Thanks so much for your patience piratesofthejellybean! We looked into this and we believe we have a solution for what you are seeing.
As I briefly explained above, the first prompt you see,
http://i.imgur.com/wStlBOQ.png will only appear if Motorola Device Manager is not already installed onto your computer - more specifically, if the Motorola Device Drivers are not already installed to your computer - which is a sub-component of Motorola Device Manager.
We believe while some of the Motorola Device Manager components are installing, the Motorola Drivers are not able to, which results in this loop you are seeing when you connect your M to the USB cable. We have seen the Motorola Device Drivers fail to install before, and usually this is tied to registry corruption.
We'd like you to try out these steps to fix the problem:
1) Download and Run the Microsoft Fix It tool
Fix problems with programs that can't be installed or uninstalled
2) You can choose to automatically fix problems, or select "Detect Problems and Let Me Select the Fixes to Apply"
3) If you choose the latter, then choose "Installing" from the next prompt
4) Find in the list "Motorola Mobile Drivers Installation x.x.x"
5) Choose "Try Uninstall" and let the wizard finish.
6) Now, install Motorola Device Manager again from the Motorola website. No need to connect your RAZR M during this step.
7) If the installation succeeds, then connect your RAZR M and confirm that you no longer see the prompt
http://i.imgur.com/wStlBOQ.png
If that doesn't work, repeat Step #2-4, and at step 5 instead choose "No, try other fixes". Then repeat step 6 and 7 again. And finally, if that doesn't work, let the wizard run automatically to find any issues on its own and fix them (choose "Detect problems and apply fixes for me" at Step #2).
We aren't exactly experts on the Microsoft Fix It tool, so we welcome you to play around with the various repair options to see if it fixes the installation of the Motorola Drivers.
Please let us know how that works out for you!