If there is ice on the coils of my window unit, is it toast?

ugh,.... CLEAN the thing. Take it OUT of the window and peel the skin (like you should have done before the cooling season started) and get in behind BOTH coils. Don't bend any copper lines or it will be trash. Use something like Clorox Cleanup and a brand new dollar store toilet brush. Wrap the controls with a walmart sack. Use a water hose and rinse it all very well.

Include the filter in the cleaning and clean that filter twice a week.

Service your air conditioner yearly and it will run like new. Guaranteed. If I see one more jackhole rattle off "its low on freon!" I'm going to choke someone.

Most people are not willing to put out any effort whatsoever and don't feel responsible for their own comfort, therefore don't really deserve air conditioning.

Doesn't anyone search the archived questions? Its not like this hasn't been asked & answered a million times......

Try cleaning the filter so it gets enough air flow.

Is the fan working properly?

Fans are cheap, and if it's icing up, the more expensive compressor

and coils are fine.

The air-conditioner will need to be serviced. It could be that the coils have gotten dirty and will need to be cleaned or it's losing coolant or it's being asked to cool too large an area.

It still has some life in it, provided you get it serviced.

Odds are the inside of the coils are dirty, and the unit isn't getting proper airflow causing it to freeze up. You probably need to pull it out and wash it out with a hose, You really need to get the coils in the rear really cleaned,