Thanks for getting back to me.
Just did what you said. Disabled my antivirus, tried a few different USB connections, four lights A B C & D are red as always and the same story, long waiting, no effect at all "Installing firmware update...", and "Update in progress".
Now looks like my M-AUDIO ProFire 2626 is effected and stops working when AMPLIFi is connected. I disabled it too, tried again & nothing. Unfortunately I do not have anyone with Win8 and I'm not sure if I want this Line 6 anymore.
I'm tired and frustrated. It sounds great, but if there's no other way to make it work or to control this devices without Remote (phone-iPad) I think I'll be returning it back. It costs me too much time and energy to figure it out, I thought it would be easy.
Anyway, thanks for you help.