The whole room is painted; walls, baseboard, window trim. Unfortunately, the pane of glass in the window has some paint on it, too. For the job to be complete, you need to clean the paint off of the glass. This is a simple process that you can accomplish yourself with a few steps.
Separate the paint on the glass from the paint on the wooden frame. Home improvement specialist Ron Hazelton recommends making a cut with your razor blade at the point where the window frame meets the glass, separating any paint on the glass from paint on the frame itself. This way, paint you clean off of the glass will not take any paint off of the wood with it.
Spray the paint on the glass with the Windex, making the surface of the glass slippery and softening the paint.
Place the razor blade on the window next to the paint, and hold it at an angle to the surface of the glass leaning away from the paint. The flatter the angle is to the window, the more easily the blade will be able to slide under the paint. With short strokes, gently scrape the paint with the razor blade.
If the Windex dries before you are finished scraping, spray the area once more. Scraping a dry window makes scratching the glass more likely. Continue scraping with the blade and spraying with the Windex as necessary until the paint is off of the glass.
When the paint is gone, spray the entire window with the Windex and wipe it down with your rag. This will eliminate any stray paint particles and leave you with an overall clean window.
Always exercise extreme caution when using razor blades, as they are sharp and can be dangerous.