I have an older house with several glass (non opening) windows. You can feel a draft on a few of them.
Does anyone know if its possible (and effective) to re-seal them?

Any info or advice would be great!

 

If they are single glass, most likely what you feel is the cold air falling down off the colder glass. Storm windows help some, as does those interior plastic cover kits. Better to replace them with double insulated/Lo-E/argon glass. While that is being done, seal up any air gaps around the frames with non-expanding foam insulation. Considering the savings in heating bills(15-25%), the cost is not that bad. If the existing frames are in good condition, you can use replacement windows, which saves considerable on labor costs since nothing on the outside and only a stop molding on the inside is disturbed.