A couple of thoughts. You indicated that you created a file. Do you mean a folder? How did you download the images? Is there any chance you used an older version of Nikon Transfer? There have been reports that Nikon Transfer does something to the files that make them unreadable in Lightroom. If you are not doing so, I suggest using a card reader. It's more reliable, and usually a lot faster than downloading from the camera. If you still have the images on the card, try downloading them just using Windows Explorer, and then try to import those into Lightroom.
Do I understand you correctly that in Win 7 and PSE you can see the photos when you connect the camera but in the Import Dialog in Lr you cannot?
Is this by chance not an approved memory card? I don't know if Lr would be bothered about a non-approved card.
These are the Nikon-approved cards for the D3200:
Back to Lr:
In the Import Dialog, top center, do you have <Copy> selected?
<Copy> is for importing images from camera / memory card;
<Add> is for importing images that are already on one of your hard drives and you do not want to change their location;
<Move> is for importing images that are already on one of your hard drives and you do want to change their location.
There is a workaround that hopefully works:
Using Windows upload the photos into a folder of your choice. Then Import them into Lr from this folder.