I’ve just had another crack at installing v.1.7.1 without success.
This is what I did:
(I am logged on as Administrator)
Did a Windows Update to ensure I had the latest version.
Attempted to Un-install v.1.6.0 - Failed.
Attempted to Install v.1.7.1. - Failed.
Tried the whole thing again in Safe mode - same results - Failure!
So I can not install or uninstall the MR816 drivers.
Any suggestions would be most welcome.
I sent you a PM, please try that and see if that works for you.
EdDoll - Many thanks for your ‘remote’ assistance - it completely solved the problem.
What a fantastic support service!
Could you explain your holy grail, please? 
Apparently there was something in the Registry stopping v.1.6 from being UN-installed and consquently stopping v.1.7.1 from being INstalled.
EdDoll sent me a private message explaining how to edit the Registry, but as I had never done that before he dialed in remotely and removed all of the v.1.6 stuff and then installed v.1.7.1
The system is working fine now.
I suggest you contact EdDoll about this as you appear to have a problem similar to the one I had.
After attempting to do it myself for several weeks (and failing) it was a pleasure to have someone who knows what they are doing step in and fix the problem.
I have a positive update concerning my issues with the MR816. I was hoping that these new drivers would solve the dropouts that I was experiencing, but sadly, they didn’t. These little dropouts have been driving me nuts ever since Steinberg released the drivers for Win7. They have made attempting to record difficult to say the least.
I have solved my dropout issues!
I downloaded the latency checker app mentioned in this thread…
http://www.steinberg.net/forum/viewtopic.php?f=31&t=1296
I was running it and everything was in the green and I was latency free until I launched my browser. The app told me I had drivers that were not cooperating with my system. So I began going through the list of things to check in that thread and disabling my network adapter was one of them. Once I did that, I was able to close and open my browser with no dropouts. From there, I tried everything in my power to make the MR816 hiccup or drop out. I started recording tracks and loading up resource hogging VSTs and instruments and everything ran without 1 glitch for hours straight!!!
Since that time, I downloaded Driver Finder and I updated the driver for my network adapter. I haven’t had a dropout even while having the network adapter active! I still plan to deactivate it during recording sessions, but it’s SO alleviating to finally understand what is causing my drop outs with the MR816 and to be able to record with confidence.
Thanks for the suggestions and help.
Does anyone know the registry fix to install this driver? I had this once before happen. If I remember right, something is changed in the registry and the driver will then install without freezing.
HELP!! I have tracking to do and I am stuck without my interface!! 
Thanks much,
~T.J. Deerinck
Nevermind! Was not the registry.
It apears there was some sort of a YFW process running, maybe a tray app or something.
Launched Task Manager and killed the process. The install completed successfully!
Thanks,
~T.J. Deerinck
Not working for me either. Downloaded TOOLS_for_MR_V171_Win64, it is installing in the Program Files (x86) ? Um, it says Win64, why is this not installing in the regular Program Files?