Windows 7 Computer Will Not Recognize Canon Vixia Hg20

2. Is the cable working fine?

Method 1

You may try to uninstall and reinstall the USB driver and see if it helps.

1. Connect the camera to the computer with the USB cable.

2. Turn on the camera.

3. Open the Device Manager:
Click the Start button, in the start search box, type in devmgmt.msc and press enter.

4. In the Device Manager window, at the left of Universal Serial Bus Controllers, click the PLUS (+) symbol.

5. Under Universal Serial Bus controllers, right-click on your Panasonic camera or USB Mass Storage Device to display the drop-down menu.

6. In the drop-down menu, click Uninstall or Remove.

7. In the Confirm Device Removal dialog box, click the OK button.

8. Restart the computer.

NOTE: After the restart, the computer should recognize the camera connection and begin reinstalling the USB driver.

Method 2

This problem occurs if the camera uses the Microsoft Windows Image Acquisition (WIA) standard to transfer pictures to the computer. Windows Vista and Windows XP SP2 use the Windows Portable Devices (WPD) standard instead of the WIA standard to import pictures and videos. The WPD standard supports many devices and device connectivity options.

To resolve this problem, configure the camera to use the Picture Transfer Protocol (PTP) standard instead of the WIA standard. For information about how to configure the camera to use the PTP standard, see the owner's manual for the camera. Or, visit the camera manufacturer's Web site.

ALSO TRY PLUGGING TO A DIFFERENT USB PORT

A digital still camera is not recognized in Windows Vista or in Windows XP
http://support.microsoft.com/kb/927836