So, I have a WIN 7 SONAR system setup that I want to test with WIN 8 (touch screen)... what is a good technique for this installation so that if WIN 8 turns out to not be compatible with my hardware drivers, I can easily revert back to WIN 7.  Since my system is already configured, I don't think I can set up a dual boot system without having to install everything all over or can I?

Thanks and I am not a computer expert so any help would be appreciated.

Jim

you need to configure you bios to boot from an external hard drive.
ive never done this and most threads ive dabbled with suggest its not a good idea.

you cant dual boot a single hd unless you reformat it/partition it.

well, do you have any other HDDs? 
(are you using several HDDs for audio, one for programs, one for samples etc?) 

If you only have one, and everything is stored/installed on that disc - you have to re-install absolutely everything. 

If you have several, it might be a bit more complicated.

Could you describe your setup? 

But - to answer your question - yes this possible and should not be an issue.

but I would have rather unplugged your OS hdd, and used a second internal HDD then do a clean install of win8 on the new HDD. 
You can always find the use of this HDD later if you decide to not go for win8.

Before you do anything, make sure you have an up-to-date backup image file (make with True Image or similar)... as this will allow you to (quickly/easily) get back to where you are now.

Once you have this, you can install Win8 on the boot HD or a secondary HD... and test/experiment.  You can change the boot priority in the motherboard's BIOS... which effectively lets you select the OS (Win7 or Win8 - assuming each is installed on a different HD)