I don't know why anyone didn't say anything about Sonar 5 and Windows 8. Honestly, I don't think Windows 8 supports Sonar 5 and vice versa. Windows 7 and 8 are used with the more updated versions of Sonar (such as 8-X versions). I use 8.5 producer edition and I wouldn't upgrade my Windows XP to 8 because I think it is not supported. Unless you plan on upgrading your Sonar version to X1 or X2, I think Windows XP would work better for you. I know this doesn't answer you midi question.

No one mentioned Sonar 5 because the OP just said " I've been using Sonar" and no mention of version. But you are totally correct and I am even wondering when they say " installed the 64bit version of Sonar 5 " was a typo. I believe 7 was the first 64 bit Sonar. Sonar 5 is from 2005. 64 bit was never dreamed of then. 

tedt- You need X2 if your running Windows 8. 

I don't know why you thought windows 8 would work with a older version like that. When you upgrade OS , you normally then need to upgrade all your software. That's why some of us pour folks are always a few years behind. Windows 7 is all you need for now and at least we know the Tascam drivers work for that OS. Not sure if they work for W8. But that said , you'll still need to run Sonar 8.5 min. Even Sonar 7 was not tested on W7 even though some report no issues.   
  

I had noted Sonar 5 in the thread title; I didn't think to put it in the post body as well.

I don't remember reading that software would not be compatible with W8.  Granted, I clearly did not do as much research as I should have.  I have, though, reinstalled Open Office and a few other programs that have run fine.  And, although I can't get the 64 bit version of Sonar 5 to run, the 32 bit, except for MIDI input seems to run fine as well.

Running XP on this machine doesn't seem like a viable option; it costs 3 times what W8 did.  Perhaps I could try a MIDI-USB converter and run MIDI into the computer from that?  Use the Tascam interface for audio?  I suppose my other option is to reload everything back on my lovely bride's HP machine that has XP.

At any rate, thanks for the help guys...I'll keep you posted.

First off, with only 2GB of memory, 64-bit Windows would be a waste. I'm surprised you could even install Windows 8 on that computer.

Changing operating systems is not like installing a new program. It takes planning and preparation, as you have learned. 

When you say it won't recognize MIDI, what do you mean? The MIDI from the Mirage? Does the little MIDI interface in the system tray (bottom right of the Windows taskbar) light up? Do you have the latest drivers for the Tascam. Does it have Windows 8 drivers? 

Sonar 5 is just too old. You really should upgrade to a newer version, but I'm afraid your computer is not up to it. I'd say you've created a mess for yourself. No offense intended...I've painted myself into corners before too. 

You just have a problem getting the midi driver set-up. Make sure you re-boot fully after uninstalling any old drivers. Re-boot then shut down and re-boot again. Sometimes registry entries can get you stuck in a weird cycle. Always start fresh with system level driver installs. I wouldn't recommend upgrading to windows 7 or 8 either. As mentioned - 64 bit operating systems on an under powered low ram hardware will open up other cans of worms.