card I am trying to read is SDHC 16Gb has 4 hour video on it
More than likely, your internal media reader is not compatible
with the technology of the SDHC memory card.
Twq possible alternatives...
1) Connect the camera to the PC via USB cable and download
the video. If autoplay is not opening when you connect the
camera...just go to...Start / My Computer...and the camera
should be recognized with a drive letter. Right click that drive
letter and from the menu....choose...Open or Explore. From
there...you should be able to copy/paste the contents of the
SDHC card to a folder on your hard drive.
2) Purchase an external USB media reader that is compatible
with the SDHC technology.
.......Volunteer J - MS-MVP...... .....This Is Not Tech Support.... ***Proceed at your own risk***