[Sci-Fi]

Just to add to the above posts:

Personally, I would try distilled white vinegar first, either a 50/50 mix with distilled water or full strength. Vinegar is slightly acidic and breaks down the water deposits/spots and is also effective in removing any wax or oily film on your windows. After rinsing, use a claybar with a quick detailer product or a car wash/water mix as a lubricant on your windows. In most cases, this method has worked well for me, YMMV.

If you want or have to go the steel wool route. Instead of #0000 steel wool, which leaves a lot of fine steel particles to vacuum or wash off, 3M makes a Scotch-Brite Never Rust soap pad that is made of plastic and works just as effectively. Can combine the pad or steel wool with some vinegar to clean your windows faster. A lot of the 99¢ and dollar stores carry the 3M starter 8 packs. Again, follow up with a claybar.

Can also use a glass polish, like One Grand Glass Polish, Zaino Z-12 Clear-View, Plexus (is for plastic but works on windows and mirrors), etc. or a paint cleanser, like S100 Shine Enhancing Cleanser, P21S Gloss Enhancing Paint Cleanser, Klasse All-In-One, or something mildly abrasive that does not contain wax. I'm not a fan of waxing windows. The mild abrasives clean up and remove water spots on the windows nicely.

Other Glass polishes require the use of a random orbit polisher, or high speed buffer or drill with a specialized pad and backing plate. I would caution the use of a high speed buffer or drill because of the possible heat generated if you overwork a spot, you may crack your glass. Using a random orbit polisher would be a lot safer. Heavy duty glass polishing using Cerium Oxide is best left for the professional glass shops.