Just sent a summary to support.
 

I was at a point a few weeks ago a big fan of Tascam and the fact they updated the drivers for my old old us1641 made me believe they are on a roll with better drivers. 
But this one model that you have can be found on different music sites to be a problem child. I have read a few times now complaints about that model. 
 
Just last night I was reading reviews for mixing boards that include USB interfaces. 
A review for the Soundcraft Signature boards and one reviewer said he had given up on using his Tascam 16x08 due to driver issues and also mentioned he was a Sonar Plat user. Had no problem using the Soundcraft at all.  
So I would either see if you can return the interface for another model or be bugging Tascam directly about this. 
 
You should not be having these issues. You have done all the right things and it should not be that hard to get a interface to work. It is not Sonar and I doubt if it's your hardware or OS. 
Proof would be to try another interface. 
 
 

Thank you all for your help.
 
This has been very disappointing. A significant waste of time.
 

ABSOLUTELY NO JOY.

jm24
Using a USB 3 port allows the computer to boot with the tascam powered-on.
 
I have just now disabled the built-in, and AMD vid card, audio interfaces.
 
And increased the number of samples to 512.
 
Same issue.
 
After the drop out, a dialog is displayed: The audio device is not accessible.
 
Yet, i can play videos and music with the windows player just after.
 
I am confused.

Try a USB 2.0 port if you have one.  Some USB 2 interfaces don't like USB 3 ports.

Absolutely not what you want to hear, but I'm running a 16x08 with the latest drivers and firmware and it's working perfectly for me on SPlat, Windows 10 x64, etc. My system specs are in my sig - pretty underpowered system for 2017!
 
The reason I mention this is just to say that this isn't a universal thing, rather than to gloat that mine works and yours doesn't. (Really sorry you're having issues, that always sucks!) As you saw in this thread, BobF uses a 16x08 successfully too, so that would suggest there's something odd going on local to your machine.
 
I definitely agree about USB3 being a problem with some devices but the big thing is that your machine won't power up with the 16x08 attached to a USB2 port. That sounds like a driver/address conflict somewhere with something important.
 
Are you in a position to do a system image to back up everything, and load a completely clean version of Windows Anniversary on your machine, no other devices connected, with basically nothing except for that and your TASCAM driver? If THAT still has the same issue then that's a pretty big problem. So what I'm suggesting is getting a fresh install of an up to date Windows Anniversary rather than letting it patch itself. I know some people have had issues with that breaking things.
 
That should be the first place to start troubleshooting, if it all boots fine, and then work backwards from there. Load in specific drivers for each bit of hardware you have and see if it boots up fine with the 16x08 on a USB2 port. If you can get as far as a clean system with all your devices connected and drivers loaded, and the SONAR makes it fail, I'm pretty sure that's something the devs would love to investigate further, because that's a pretty big deal.

Thank yous guys for your responses. I appreciate gloating when required.
 
As i wrote above: Two fresh installations of w10, from anniversary disks.
The computer will not boot with the tascam attached to a usb2 port. Usb3 is fine.
Obviously the tascam works with windows sounds and music and videos.
Just not with an asio program.
Reaper also is not interested.
 
I have tried on two computers. And installed a NEC based usb card that another poster said fixed his problem with noise and the 16x08. This is a usb 3 card. The computer boots, and windows likes sending sound to the tascam.
 
Maybe it has something to do with AMD boards and the asio drivers? Maybe need an intel board. That will make me sad. Until this problem the 8-core is running happy.
 
I have read posts from others on other forums that they could not get it to work and gave up. 
 
So, two computers, and a new usb card, windows sounds work on both, and sonar and reaper refuse to be happy.
 
Waiting for a response from tascam.
 
Meanwhile, back at the ranch, I am using the built-in sound card to get some editing done. Will attach an old emu usb that was working before i lost my brain and tried to use the tascam.
 
Again, thanks for the help.

It's NOT just SONAR  (Win8.1x64)
 
SONAR
Reaper
Mixcraft
Tracktion
Studio 1-3
Cubase AI
 
The TASCAM 16x08 crackles, pops, farts, snorts and coughs.  In my own use, it's worse with IKM software, but it's a PITA for sure.  The latest drivers seem to be worse in some ways, better in others.
 
Using my FA06 as an interface, a Zoom R24, a UMC404HD ... all perform flawlessly, though limited in other ways.
 
It is a TURD that polish nor lipstick will make better.  I can fiddle with settings and get along with it, but if a new system/MB with Intel USB doesn't solve the problem(s), this thing will go to the electronics recycle bin.
 
It is NOT SONAR

this is sad.  That gibson/tascam/CW have created a product that should work great and does not is just sad.
 

Yeah, this is pretty sucky for sure. I'm starting to lean towards it being a faulty 16x08 like was mentioned earlier.

Have you tried having a fiddle with your BIOS settings in regards to how it handles USB devices? I know there's some legacy settings which might change how things talk at the hardware level, even before it gets to Windows.

No other good suggestions here if you have no joy from that or useful info from TASCAM.

Is there a chance of trying a replacement 16x08 and seeing if the symptoms persist? That would rule out a hardware issue.

I don't think anyone would blame you if you decided to just cut your losses and get a new interface, honestly.