How to Export a Low Resolution Picture:
Verify that the option File > Free Size is checked.
Choose iNMR > Preferences and click Output. The pair of parameters that set the resolution of the picture is located at the bottom of this panel: Resolution and Line Thickness when copying and exporting. The most important one is the Line Thickness. If you set both parameters to 1, the picture will be identical to what you see into the iNMR window.
Use the standard Copy & Paste mechanism to export the picture. There's no need to select it; the command Edit > Copy is always enabled. If you prefer the Drag & Drop way, Choose Tools > Dragger, then click inside the window and drag to the final destination (that's what the dragger tool is all about).
If an external program doesn't accept a picture coming from iNMR, you can use the free converter called PDF 2 PICT. First copy the picture into the PDF 2 PICT window, then from here to the unfriendly program.