After you have adjusted your image make you save it, a pop up box will automatically open if you dont click the save button. Once your copy has been saved you can use it as is or convert it, if you convert it save it to a new folder so you can find it easily, you can then upload to fb via this folder.
If you are not saving the file after adjustment then this could be why its converting back to original state when you move it to your desktop.

Try to complete uninstalling Quicktime and re-installing again. It should work . Regards.

Are clicking the apply button after setting your crop??

It should install as any normal program should. Is it in your start menu in the program list. If not you may want to try and reinstall it as it should work without having to plug anything in.

At the bottom right of the Adjustments window, there is a Save and Save As button

What are trying to update? the camera or View NX. If its the camera you should be able to do it by setting the camera as a storage device, look in your manual how to do this, there should be exact instruction on how to update your firmware on the Nikon website.

At the bottom right of the Adjustments window, there is a Save and Save As button

Picturetown is just another feature. You don't need to use Picturetown if you don't want

Easiest way is to do all the editing you need to do and then click the save button, not the save as, at the bottom of the adjustment menu. Once you have done this make sure your adjusted image is selected and click on the convert button at the top, there you can then set image to jpeg, tiff etc and also set the image size and quality.

If you are trying to convert a jpeg then there is not a lot you can do with it, if, however, it is a NEF you are trying to convert then that is reasonably easy to do. Select the image you want to convert then click on the edit tab at the top of the page. To the right you will see the adjustments, under picture control click on the launch utility button, then in the stored controls select monochrome, once you have done this click the toning drop down and select sepia, you can adjust the intensity here as well. Once you have done this click new and give it a name, click ok then click quit. Once you have done this then go to the picture control click on the drop down and you will see your new preset at the bottom, click on it and your pic will turn to sepia, save as normal, job done.

Go to Edit - Options - Background Colour and change it there.