I have installed many windows with it and think that is the best application for it. Most windows have an inner ring that that screws to the window. Many times the ring and window will not tighten to the structure either because the structure varies in thickness or the inner ring is made for a thicker structure. The butyl tape provides a seal as well as a gap filler. Butyl tape is somesimes confused with a window putty. Both of these products are sold at RV supply stores and usually sit next to each other. The butyl tape is more like silly putty and the other product is more like that oily clay we used to play with in elementary shcool. There are also different types of butyl tape, some are "thicker" and a little less stickey than others. While butyl tape is not an adhesive it does "stick" to surfaces and is a very good sealer for areas like windows. I ust only for bedding windows where a gap filler is needed and leave the hardware bedding to Sika Flex or 5200.
---Joel---