Can i uninstall ETW and reinstall it without updates?
I have to wait till October to get the right trainer, so is this possible?
Well you can burn the installed files to your DVD(s) and delete the it from your HDD. After you get your trainers, you can copy them from the DVD(s) to your HDD again. Hope this helps.
But yes, just don't do anything with the steam and its client files, or else it will be long gone. Just backup the game folder.