Yes, cleaning windows is simplified by pressure washing, but you need to take special precautions when doing so. Note, never use a ladder to pressure wash windows or siding. In the case of a two-story structure, use a second-story nozzle kit, or a telescoping extension wand.
If the window frames are aluminum or vinyl, pressure washing should not be a problem. Wood-framed windows require special attention to detail. Review the glazing between the frame and glass; it should be intact and solid. Take a moment to look at the weather stripping on the window and the caulking around the frame where it meets the siding. Both need to be in good condition so water cannot penetrate into the structure.
Should you have double-hung windows, remove the screens if possible. This will make sure you can easily clean all of the glass. You can wash the removed screens separately with the lower pressure white nozzle or your garden hose sprayer by spraying water through one side. Turn them around and spray the other side. Place the screens aside to air dry.
To begin washing the windows, use the white, 40o nozzle to wash down the windows to remove loose debris, bugs & spider webs. Keeping the nozzle at least three feet away from the glass, start at the top of the window and make your way downward.
Soap/detergent is the next step. You can find pressure washer-approved soap/detergent at your local home center or online that is safe to use on windows and siding. Using the black low-pressure nozzle, apply the soap to the windows. It is recommended to only soap a few windows at a time. By doing this, you can wash the soap off before it dries.
Once again, you will use the white nozzle to rinse away the soap. As before, keep the nozzle at least three feet from the glass and start at the top of the window.
While the windows are still wet you may want to open them so you can wipe out the sills of any dirt and debris then reclose the windows. Once they have dried, place the screens back into the window frames.