Sort of on topic,,, so on a new OS install Is it best to let all windows updates do their thing BEFORE installing your audio software?? I just did it backwards and it's not running very good DPCLAT wise... Never had the red spikes before... So I was tempting the re install Sonar/  Focusrite driver plan??  I do remember a few of my software programs installed C++ in the mess... Then Windows update did a bunch too.. 

It should not matter at all in theory but I would definately recommended running windows update several times directly after installing Windows before installing any other software just for a smoother ride.

After you've installed all your software run it again.

Guitarpima
A little off topic about A3. I don't understand why it has two inputs in the audio setup. I set the 2nd one to something that would get no signal and would you believe it sounded better? (shaking my head)

Not sure if this is what you mean, but you can enable stereo routing in Amplitube via 2 of the 8 routing presets (the numbers on the top left of the window). Numbers 2 and 6 give you the option of changing the "mono in" setting to "stereo in," after which you can then process the left and right channels separately with different stomps, amps, cabs and racks. 

joakes
In Control Panel -> Programmes, I have multiple entries for Visual C++ 2005, 2008, 2010 and 2012. OK, given some are x86 and others x64, can I delete the double entries ?
 
I get the impression every programme using such libraries installs its own version. I am probably wrong, but then why do I have, for example, 5 different version numbers of C++ 2008 (x64) Redistributabl ?
 
Yours perplexed !

 
I would suggest keeping both the x86 and x64 versions; the WOW64 emulator will probably need to hook into the x86 version(s) for 32-bit application support.
 
As I understand it, you can have multiple versions of the same redistributable installed, but it is the most recent version which will be used.  e.g. I have 3x x86 2008 and 3x x64 2008 redistributable packages installed on my work laptop, but that's really like a record of install history; only the code from the most recent version(s) of the runtimes will be used.  You could roll-back an install if required, the installer should be able to revert the runtime library version without causing any problems.
 
As for the OP's question, as re-installing the redistributable runtime takes very little time, it makes sense to try this first.  I'm not 100% what happens if the version you are trying to reinstall is earlier than the latest which is installed, so in that case it would make sense to uninstall any later versions first.  I would take the approach of uninstalling all versions before reinstalling the version I wanted.
 

Please do not uninstall C++ libraries. Upgrade yes, repair yes, but don't uninstall (unless there is no option) as it could lead to far more serious problems (you are playing with fire).

And C++ libraries aren't ever an issue until you see a specific related issue logged. If in any doubt run windows update (including optional updates) several times which will sort out most problems.