Steve, random thought. Are there any MOBO driver updates?

USB drivers (the chips, not the software) do fail sometimes. I've seen it happen twice that I can recall, requiring the installation of an add-on USB card. There is also an internal cable that connects the case-mounted socket to the motherboard. I once solved an intermittent USB port problem after discovering the cable was not seated properly.

There is also an internal cable that connects the case-mounted socket to the motherboard. I once solved an intermittent USB port problem after discovering the cable was not seated properly.

This  ^^^^^

Another thing that can cause it is hidden device references causing conflicts with currently active drivers.

To find out if you have a load of those interfering with your current (software) driivers, do this:

Open a Command Prompt window.  Copy and paste this text into it.

set DEVMGR_SHOW_NONPRESENT_DEVICES=1
start devmgmt.msc

Press Return.

Then from the View Menu in the resultant Device Manager select Show Hidden Devices.

Check for any 'greyed out' devices under USB controllers 'right click' on any of those and select uninstall for each greyed out entry.  Do the same for hidden devices under 'Human Interface Devices', 'Keyboards' and 'Mice and other pointing devices'.

Also check 'Sound video and game controllers' but don't uninstall any of the greyed devices in there unless you know they relate specifically to any old audio interfaces you no longer use or they are just duplicated old TonePort drivers. Leave any Microsoft entries alone.

Reboot afterwards and check again to see if everything is working OK.

Thanks Ed/Dave/Jon

It's a bit too late for me to start fiddling about with this kind of stuff now, but I'll check it all out tomorrow.

my previous DAW would FRY any USB device plugged into the front ports.  I checked the cables, made sure they were seated correctly and not turned the wrong direction (which shouldn't be possible, but worse things have happened) - could not figure it out.  decided it must have been a problem on the motherboard.

Jonbouy

There is also an internal cable that connects the case-mounted socket to the motherboard. I once solved an intermittent USB port problem after discovering the cable was not seated properly.

This  ^^^^^ 

Gents, is this a relatively 'easy' procedure for someone who's never even taken the back off a PC before?
 
Or would I maybe be better advised to pay someone to take a look at this problem?
 
I really need to get this sorted as it's now happening two or three times a day (or more) - a right royal PITA 
 
Just to clarify, the problem isn't really intermittent as such - once one of the USB ports has 'failed', it has never started working again in the same session. I sometimes hear the standard Windows USB detection/disconnection sound and then the device attached stops responding. However, the device is still 'connected' to my computer because, for instance, my backlit keyboard stays lit, and the meters on my TonePort are still lit.
 
Sometimes a single slot will stop working, and I can plug the device into a free port and it will start working immediately. Sometimes, all the USB's go down together.
 
However, when I do get a failure, rebooting my PC (and even leaving all the devices connected to the slots they are in when failure occurs) solves the problem every time. All USB ports work fine immediately after a reboot. The time it takes between that and the next failure has been as short as a few minutes, up to several hours.

Jonbouy

Another thing that can cause it is hidden device references causing conflicts with currently active drivers.

To find out if you have a load of those interfering with your current (software) driivers, do this:

Open a Command Prompt window.  Copy and paste this text into it.

set DEVMGR_SHOW_NONPRESENT_DEVICES=1
start devmgmt.msc

Press Return.

Then from the View Menu in the resultant Device Manager select Show Hidden Devices.

Check for any 'greyed out' devices under USB controllers 'right click' on any of those and select uninstall for each greyed out entry.  Do the same for hidden devices under 'Human Interface Devices', 'Keyboards' and 'Mice and other pointing devices'.

Also check 'Sound video and game controllers' but don't uninstall any of the greyed devices in there unless you know they relate specifically to any old audio interfaces you no longer use or they are just duplicated old TonePort drivers. Leave any Microsoft entries alone.

Reboot afterwards and check again to see if everything is working OK.

 
Jon, I tried doing this, but the Command Prompt won't allow me to paste anything into it. I tried typing what you showed me in there but when I press Enter, nothing happens; except for a new command line appears:
 
 
 
 
I have opened Device Manager from the Control Panel and clicked on View > Show Hidden Devices. I've shown everything that's there (and expanded the fields that might be important?) in these screenshots; Incidentally, the only 'Hidden' devices that show up are the "Non-Plug and Play Drivers" I've highlighted:
 


 
 
Nothing seems to be greyed out as far as I can tell. Here's the complete list of what's inside when I expand the Non-Plug and Play category:
 


 
 
 
 
Thanks again in advance
 
 
 
 

Steve you need to type those commands in on separate lines.

set DEVMGR_SHOW_NONPRESENT_DEVICES=1

Is the important line, press return after that.

The other line just starts the device manager, you can do that manually like you did here as long as you've entered the Environment Variable as above.

Don't worry about any of the Device Manager devices unless they are in the locations I've already specified.  DONT touch anything under Non Plug and Play Devices.

If you ever want to paste text into a command prompt  Ctrl/v is the key combination to do that.

What we want to do here is to eliminate any software problems that might be causing issues before resorting to having to pay for a fix.

Hey Jon, thanks for sticking with me mate
 
Ctr+V is still not working for the Command Prompt, but I typed in the first line and clicked Enter and again, all I get is another command line open up:
 

 
When I hit Enter:
 

 
 
Should something actually happen to confirm that I've 'done something'. The line to open the Device Manager did work BTW, but when I hit the show 'hidden devices' the list is identical to what I got before.
 
And thanks for bearing in mind I'm fumbling around in the dark here mate, none of this really means anything to me

No you've got it right.

It just confirms you have no hidden devices.

You seem to have plenty of input devices though.  Try just with your keyboard, mouse and audio interface and unplug any thing else that isn't necessary, reboot and see what happens from there.

Also if you can let us see what you have under Mice and Keyboards.