The phrase “the window of opportunity” seems not wholly satisfactory
Admittedly you can see through a window unless you have thick net curtains but how many of us would be able to leap out of the window and seize the opportunity by the throat,if you see what I mean? And if you were in the attic you’d be dead before you got there…so what we need are “doors of opportunity”

The problem with that is you can’s see through a door unless it’s either got a window or is a glass door..So if you want success try living outside in a transparent tent where nothing will get in your way if anything passes by and your will get free publicity
I expect the phrase was made up by someone who writes speeches for politicians.
If you want a to succeed you must grasp the windows of opportunity as they go by and squeeze every last drop of rum out of them [try the tygers of wrath too]
She was only a little window but she was the window for me
Do not ask what your windows can do for you but what you can do for your windows.
Look through the windows and seize the day.Unless it’s a dark night in which case visit a brothel if they have windows
And one day all our children will be able to choose their own windows..red,yellow ,……………..mix your own…..free windows ..
Windows are the eyes of the house
Don’t be shy if opportunity peeks into your window.Peek right back at it…
Ich bin ein Window! Moi aussi.Ma femme!
Where is she now, the rich widow of my opportunity?
To look or not to look.Out of a selection
Never close the door in case someone wealthy passes by on the other side.and merely glances at your window.
Now is the Window of our discontent made gloriously plumper with our sunny walk
One good window deserves another.
I’ll be your window, if you open your door
Windows,they ought to be taxed I say.
Windows.. they give you an illusion of being in the sun but did you know we can see in…and we saw you and the mirror on your ceiling…anything to say in your pretence?