'first window' is correct and usable in written English.
It is typically used to refer to the first of two or more windows. For example: We went to the store, but the first window we looked in had nothing that we needed.
First window is on Wednesday and that is not certain.
"We are making online our first window," Mr. Rosenberg said.
Joan George was welcomed to the first window.
The first window for "Sunny" is on cable television, which relies on subscriber revenue.
The spreadsheet, regulators say, presents the public with its first window into the swaps market.
Now, in her written testimony, Ms. White provided the first window into her priorities as an S.E.C. chief.
Ms. White's testimony "provided the first window into her priorities as an S.E.C. chief," Mr. Protess says.
"I noticed movement in the first window — maybe a male, maybe a white sheet," he recalled later.
"The first window broke on Flatbush Avenue about 10 minutes after the blackout" began, Mr. Kelly said yesterday.
Ten minutes or so after the blackout began, the first looter broke the first window, on Flatbush Avenue in Brooklyn.
The first window display she mounted -- which had a stars-and-stripes theme for the Fourth of July -- caused fireworks.
