Here is my first experience with Scope4.5 and Scope5 at the same time on my computer.
After installing S.5 I had to enter the key for S.5 -> haven't them yet.
I tried to start S4.5 -> not possible because the new drivers aren't compatible with S4.5
Changing the drivers in the Windows-Xp-Hardware-Manager -> no effect.
So I stated the S4.5 installer and it prompted me to install the old drivers - i did it without installing
the whole Software 4.5 --> after a restart S4.5 worked again!
So I wait for the keys for S.5
BTW: My Luna wasn't recognized by S5 only Pulsar II and Pulsar XTC
Harry