DM 42 Connect to PC

[Graan]

Hello
I tried to connect my DM 42 to a PC (Win 7 32 bit) . I got the message "the driver was not successfully installed" several times. Tried Another PC w Win 7 64 bit and got the same message.
Then I tried a third PC and wiggled the contact to the calculator. The drive now showed up. But when just touching the contact the Connection was lost again.
I dont know if a special cabel is needed , but I used 2 different cables for my Samsung Galaxy phone. Seems they are the right ones, or am I wrong?
Anyone else had this issue?