Okay I opened cmd
c:\Users\miner2>
And what do I have to do now
i filled in you're line : lolMiner.exe --list devices
but it doesn't recognize
Almost ... you forgot one "-"
its lolMiner.exe --list-devices
If you put that in a bat the problem will start, print but close instantly ... therefore writing it to bat is no good idea. With cmd is better

it put in device 0,1,2,3,4 now and they work
if I add number 5 it doesn't work anymore and screen flickers , is there a maximum of GPU's ?
No, there is no maximum - we had people running 6+ cards. Only problem may be if that one is used for graphics output or the CPU is too weak, because each solution found has to be checked by CPU if its below target and then send to host. It seems somewhere your rig runs out of resources.