Ultimate I Spy: Window Location — Need More Details

I can't locate "the window" without knowing which Ultimate I Spy product you mean.

Possibilities

• Book series (Scholastic) — "Ultimate I Spy" hardcovers (2000s)
• CD-ROM games — I Spy Spooky Mansion, I Spy Fantasy, etc.
• Mobile apps — I Spy With My Little Eye variants
• Board game — I Spy Eagle Eye, I Spy Memory Game
• Wii/DS game — Ultimate I Spy (2008, Wii/DS)

What to Provide

• Platform (Book, PC, Wii, DS, Mobile, Board)
• Specific title / cover art description
• Context: "Window" in a riddle? A hidden object? A level transition?

Reply with details and I'll pinpoint it.