Need help installing Acceleration onto a secondary drive.

I've been away a few years now due to a sickness I have for Sim Racing. So first I'd like to say hello to all. Although I'm obsessed with Sim Racing, every Rig I own has a set of flight controls and include both Flight Simulator X and Prepar3D. I've run into a problem installing FSX + Acceleration my new PC. A few years back my original install CD had gotten scratched and I had to be replaced. The new copy I bought was an ISO. Using Demon Tools the ISO makes for a fast and clean install as long as I'm installing it on the "C" drive. The problem is, I don't run my programs from my "C" drive. All large programs and games, including Simulations are installed on storage drives. The FSX portion of the ISO gives me the option to choose where to install too, but when I run they Acceleration ISO this option is not listed and without FSX being on the "C" drive it won't install. The "C" drive on the system is a 256 GB SSD, making it to small for FSX along with all extra aircraft and scenery. I'm sure there is a key command that would allow me to point the Acceleration to where FSX is, but my computer knowledge is all self taught. True I build some of the fastest systems around but I've never taken a computer class and keyboarding seems to be a lost art. If anyone knows a way to redirect an ISO install please help. I could buy yet another copy of FSX but I really prefer the speed of the ISO or Flash Drive. Thanks and Keep it in the air. James Wheat