After installing Platinum, Asio "interface Status: Unavailable"? [SOLVED]

Everything was working fine in Pro, but after uninstalling pro and installing Platinum I'm now getting an error in the Asio4All panel that shows a red X on my audio interface output. (Inputs appear to be okay.) A hint box pops up that suggests maybe something is conflicting, possibly the MS midi synth. I searched the 'net for info, and it looks like this is a common issue, yet I couldn't find a single useful answer.
 
I can't find any info on how to disable the midi synth, but I'm not convinced this is the culprit anyway. In the audio device settings, Exclusive mode is NOT enabled. In Sonar, "share drivers with other apps" is checked. Many, MANY reboots didn't help. Tried deleting the aud.ini's from both Pro and Plat (not sure why the Pro one is still there) to force it to make a new one, but that didn't help.
 
What is frustrating is that the issue appears to be specific to Sonar, because if I run Addictive Drums in standalone mode, the output works just fine. It's as though Sonar is conflicting with itself?
 
I'm just using the built-in Realtek audio in my PC, and it was working great yesterday. I was actually amazed that I didn't have to tweak anything to get it going with Pro, I was expecting a fight. So I dunno what I broke, but it's broke. :(
 
Win 7 pro 64
Intel Core i7-4770 3.4 GHz
24GB ram
 
EDIT: BLARRGH! Seconds after posting this I thought "maybe I should see what happens when I ENABLE exclusive mode?" Well, that fixed it. So of COURSE the thing I try after posting works. GRRRR.
 
But now I have a new question: I disabled my Behringer USB mixer while I was troubleshooting and it vanished from the playback devices list. Now I can't figure out how to get it back. If I look in Device Manager, it says it's enabled, but it doesn't show up on the playback devices panel, so I can't configure it or set it up with a volume control. Tried plugging and unplugging, but that didn't do anything.

Tried that, no dice. :( Also noticed that the exclusive mode settings didn't stick and I had to set them again. Also Addictive Drums is now crashing when I try to launch it. WTF did I do?

is the Behringer USB mixer also an audio interface with true ASIO drivers? in which case you should delete ASIO4All from the computer and use the Behr.

You seem to have a number of threads going at the same time giving a really fragmented picture. Can you please confirm you have fully removed ASIO4ALL please. All your issues in the other threads could be related to this.

Wise choice - you will be much happier in the long run with a real interface.  Happy shopping.