Ctrl-U to Unselect All (or right-click the selection > Unselect All - where the shortcut key combo is also shown in the context-menu entry)
Bear in mind that running all your profiles at once / in parallel will likely be overloading/slowing down your PC (the profiles will almost certainly be contending for something (disk access, network access...) and possibly for multiple resource permutations. The execution time is often actually longer by the time they finish 'arguing' than if you ran them sequentially. You should maybe consider creating a Group, adding the profiles to it, and then running the Group (which will by default run them in sequence). Or, Queue them.
Bear in mind that running all your profiles at once / in parallel will likely be overloading/slowing down your PC (the profiles will almost certainly be contending for something (disk access, network access...) and possibly for multiple resource permutations. The execution time is often actually longer by the time they finish 'arguing' than if you ran them sequentially. You should maybe consider creating a Group, adding the profiles to it, and then running the Group (which will by default run them in sequence). Or, Queue them.