The problem is probably not with SONAR but interactions with Windows. So different software or an upgrade would likely yield the same results. I highly recommend going into Device Manager and disabling (not necessarily uninstalling) ALL audio drivers under Sound, Video, and Game Controllers except for ASIO4ALL and see what happens.

I've done some of that but will have another attempt. Back to you soon..I appreciate your help

In Device Manager I'm now seeing

Other devices ?
? audio Device on High Definition audio Buss
? ". ". , ". ". "
? Ethernet Controller

Tried above suggestions ..still the blasted X

Try disabling that  audio Device on High Definition audio Buss

Ok thanks....I've done that....still the X
I'm afraid I'm maybe going to admit defeat...I've had bad upgrade glitches in the past and I was hoping that with the Akai it would only be a small one ...but this is the mother of them all.

This forum is littered with hours wasted by people using ASIO4ALL. It definitely can work, and I admire that they've managed to trick Windows into doing something it was never intended to do, but it's a kludge.
 
Also the system properties in ASIO4ALL can be kind of confusing, make sure they're squared away. Another option is simply to live with WDM or MME...
 
Don't forget that sometimes you have to restart when you make a change in device manager.

Craig Anderton is quite correct in that many changes in the device manager require a full restart of your CPU.  Try a cold boot (turn off your machine and wait for a few minutes, then restart).

ASIO4ALL and "Home Studio" really don't belong in the same thread title. And looking at the documentation and specs on the Akai, I'm not sure it qualifies to be part of a "studio", either. It has no native ASIO driver, and only supports 44.1kHz x 16-bit audio. The documentation itself recommends using ASIO4ALL if latency is too high, which I have never seen another interface manufacturere do. The documentation doesn't even refer to a native driver type at all, but presumably it will be available as a WDM device if you set that mode in SONAR.
 
Based on everything I'm seeing, I would strongly recommend you return the Akai to the seller if possible, and get something, anything, that comes with a native ASIO driver. The Akai seems like something that would have come to market 15 years ago, and be selling on eBay for $40 now. There are many superior interfaces out there for the price, though they won't have analog meters - a questionable value - and may only offer two channels.
 
 

I really do appreciate everyone's help and input here.
I'm afraid the WDM options don't work either.

I find it quite abysmal that I've bought something that clearly has inherent problems that are known and yet is still advertised without any prior advice or warning regarding compatibility with certain DAWs.

As it is now I've wasted three full days spent £140 and instead of improving my system it has crashed my studio and caused hours of frustrating headaches.

But again. Thanks for everyone's input.

Try to return it. Hopefully the store will understand.