Sliding windows are usually designed to be lifted out of their tracks for cleaning. This is particularly helpful if the window is several stories off the ground and you want to clean the inside and outside of the window, as well as the tracks, at the same time. Most sliding windows operate from both sides, but a few will have one fixed panel and one that moves. You can usually lift out the windows that move after locating the lift blocks.
Slide your window open so that it goes past the lift blocks. Place your hands on either side of the window and lift it upward into the upper track. The window should lift above the top of the bottom track. Pull the window toward you. Place the window on old towels positioned on a vinyl or tile floor. Repeat this with the second window.
Fill a 20-oz. spray bottle with water. Add 2 tbsp. of distilled white vinegar and mix well.
Spray the windows with the solution and scrub them with a nylon scrub brush in areas where there are pieces of stuck debris. Wash them with more solution and a wash cloth. Dry the windows with an old terry towel.
Wad up old newspapers and polish the glass. The newspaper will remove the traces of chemicals that will leave streaks on the glass.
Vacuum the window tracks to remove dirt. Use a small, old toothbrush or toothpicks in the corners if dirt is matted or clumped up. Make sure that any drain holes are open and draining to the outside, as this prevents water damage.
Spray the tracks and scrub them with the nylon brush. Try not to grind the dirt into the paint. Mop up the grimy dirt immediately with old towels.
Re-install your windows by reversing the order of how you removed them.