Exposure Help (Camera Screen to Computer Screen)?

When I take pictures it shows that my exposure is right on but once I take into NXview2 it shows up really dark. Can someone please tell me why?

Additional Information:
I have a nikon D3100
I use GIMP and NXview2 to edit
And I shoot RAW

Added (1). How do you calibrate your camera? Link to resources?

The first thing that comes to my mind is… Monitor calibration. I calibrate mine every 30 days (or sooner if there's a driver update).

You need to calibrate your monitor.

In addition to calibrating and profiling your monitor, make sure that your cameras LCD is set to -0-.

My guess is that you set it up to +1 or +2 for some reason and now think that your exposures are just fine when they are in fact one or two stops underexposed.

Make sure too, that the EV setting on your camera is set to -0- as well.

Then use the cameras light meter correctly and all should be just fine

Along with the other answers, learn to measure your exposure by knowing how to read your histogram. The monitor image on the camera is not an accurate display of exposure values.

Monitor calibration means calibration of your COMPUTER monitor, not your camera. The tools can range from very expensive and difficult to use, to much less costly, easy to use, and still very effective. Here is one that is popular, easy, low priced, and works very well:

http://www.bhphotovideo.com/...ystem.html