: Check your email (including the spam folder) for a receipt from "Visual Watermark." Windows Watermark Confusion : If you are seeing an "Activate Windows"

Copying a key from a PDF or email often includes an invisible trailing space. Solution: Paste the key into Notepad (Windows) or TextEdit (Mac) first to strip formatting, then manually retype the last four characters.

These marks serve two purposes: (making theft difficult) and attribution (identifying the owner).

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