If you have problems with the opening and closing of Windows, you can apply some wax on the tracking. It's been a long time since anyone used this thing, I thought to share it with the owners and professionals. My grandmother was a master carpenter and he always had a small candle in his nails or toolbox.
I've personally tried wax, grease, silicone-based lubricant, oil, vegetable oil and wax to work on the best. I sprayed silicone lubricant on my windows and in a few months there was a nice collection of dirt, where I had applied the lubricant on the track and it was gummed around the functional parts of the window. The dirt eventually made the window more difficult to slide and had to be dismantled, cleaned and reassembled.
I used silicone lubricant on a number of things and I had the same results. The wax can also attract dirt but does not seem to collect as much as oil, grease and other lubricants.
The wax used as a lubricant often works best on horizontal sliding windows, these are windows that slide from right to left and you will have to lubricate the tracking as the wheels roll. Some windows have teflon inserts on the sliding section of the window. Anyway, you can apply the wax to the bottom of the window and soon you will have a window that slides back and forth with ease.
If you apply the wax and it does not make it easy to slip the window, you may have a problem with the rollers on the window, teflon inserts, or tracking. Sometimes the window track and rollers just need to be cleaned so that the window can slide effortlessly.