Painted over screws and air return vents

Use a utility knife to cut the paint around the vent. Take a putty knife or a screwdriver and scrape away the paint.

Sometimes you can hit the screw with a hammer to loosen the grip of the paint. Place a screwdriver or nail driver on the screw and tap with a hammer.

Try brushing the screws with the some fingernail polish remover.. it should have some effect on deteriorating the paint. Then the knife or screw driver to break the screws loose. Do the same things around the edges of the vents. My husband uses gasoline but the smell is atrocious. The atectate should work. You can "brush" it on with a Qtip. To hold the nail polish remover in, cover it with plasitic wrap and tape the edges with painters tape.

You may also need to use that utility knife to cut the paint out of the slots in the screws to get a screwdriver in there.

Ditto what Roxaneg and Trudy said. Just be careful you have a sharpe, new blade in the knife so you get a clean cut between the vent edge and the wall. Otherwise you could pull a chunk of paint/plaster off the wall when removing the vent. Then you gotta do a patch. More than likely you will want to replace the vent. You can scrape and repaint the old one to match if you want to go through the effort, but a new one is easier and smoother to paint or simply buy a complimentary color. Also when you buy the replacement vent, it is a good idea to take the old one along or carefully measure the old one. They come in different sizes and sometimes they look like a match until you get it home and find out you are 1/4 inch off then have to treck back to the store.

Just work at it. There is no other way.

Try using a power screwdriver in reverse

I have used an exacto blade and safety razor blades. Clean the screws by cutting into the paint so you can get the screwdriver in it and around it so it isn't so hard to start getting the screw started coming out. Use the blade to carefully cut around the edges of the vent until you have it loose. Be careful to not cut too far up, try to keep the cut right where it meets the wall. When you take the vent cover off, do it slowly in case there are spots that didn't cut all the way through the paint and you won't damage the drywall behind it.

I've spent too many hours trying different things for this! Then I thought of a quick and easy solution. I put a cutting wheel on my Dremel and cut around the screws. Then I popped the cover off (after cutting around the edges with a utility knife). At this point I was able to get channel locks on the screws and back them out. Took less than 10 minutes.