You need to wash them inside and out. Here is how!
It's a real pain but they need cleaned. You'll have to wash each side which I know can be difficult if some can't easily be accessed.
Be sure to wash windows early morning or late evening when sun is not shining directly on the glass, to prevent smears. Also note that some window manufacturers will invalidate the warranty if you use oroducts to clean, containing ammonia or alcohol.
If thorough cleaning with methods as described in an earlier post (today) don't work, seals may be clogged or broken. Check to see if "weep holes" (located in corners) are not clogged with insect matter, using a pipe cleaner, or similar tool. If no imprevement, window seals will need replaced.
Sprayway and newspaper.