Cleaning and Stain Removal - Hard Water Spots on Bedroom Window

I have severe hard water spots on the outside of my bedroom window.

I have tried the following solutions as a result of reading other forums and NONE of them did ANYTHING:

-Pure vinegar
-Undiluted CLR
-Glass oven cleaner

Some forums recommended trying something called SpotX, Number 7 Polishing Compound, and Barkeeper's Friend.

I'm getting tired of spending money on all these products. Does anyone have any real experience with severe, dried in hard water spots on windows?

Thank you in advance!

How old are the windows? keep in mind depending on the air quality in your area there may be conditions that are causing pitting in the windows and as a result they are damaged beyond cleaning..older windows had inperfections that may this condition stick out more... the only other thing i can suggest is very fine steel wool or a fresh scraper blade

The windows are 3 years old. I live on the ground floor of a New York City (Brooklyn) apartment that faces a small backyard. There are no sprinklers, and the air is fairly clean for NYC.

I was told by someone to use fine steel wool and a #7 polishing compound. I don't believe any chemicals will dissolve the minerals at this point. I think I need to actually take off these layers on the window.

Any further recommendations?

Thank you!

scraper blade..for 3 yr old windows with todays standards...hard to think what wouldnt come off the windows