I was planning to use Halion 6 with Cubase 9 on win 10 64 bit pro on a new pc that I am building in the next couple of weeks, but since I am also keeping my old machine I wanted to be able to run Halion 5 on it (with Cubase 8.5 on win 7 64 bit)
Is this possible by keeping the license on the USB elicenser, or will I have to upgrade to Halion 6 on the old machine too? (but I read it has problems with win7)
normally for Steinberg, a higher version licence automatically allows running a lower version product. However, for some technical reason, this rule does not hold for HALion 6. Therefore, after purchasing HALion 6 you will have to ask Steinberg separatelly for an additional HALion 5 licence because your original HALion 5 licence will get surrendered during the upgrade process.
So, you will need the HALion 6 licence as well as the HALion 5 licence and both these licences can be stored on the same USB key but then you will have to move it between those two computers. Alternatively, you can buy an additional USB key and move one of the licences to it.