No connection with iqInterface or USB driver installion fails

If you cannot connect to iqInterface from PC over comport or USB (or USB driver installation fails), try to clean unused comports following the next steps for Windows 7:

• press the start button, right click on “Computer” in the right column of start menu and select “Properties”
• system information window should be opened
• press “Advanced system settings” on left panel
• press “Enviroment variables” button
• add new user enviroment variable with name devmgr_show_details and value 1
• add another user enviroment variable with namedevmgr_show_nonpresent_devices and also value 1
• press ok to close all settings windows
• press “Device Manager” on left panel of system information window
• go to “View” in main menu and activate “Show hidden devices”
• now under “Ports (COM & LPT)” subtree you can see all inactive comports
• right click on each of them and select “uninstall”, also including maybe currently connected iqinterface
• disconnect the iqInterface cable from PC and connect it again
• if neended try to reinstall USB driver from usb_driver\Windows XP_7_8\CDM20830_Setup.exe on USB stick shipped with iqInterface