Windows 10 and 11 (installation/upgrade). Official License: Linked to your Microsoft account. Format: 25-digit code (e.g., PRODUCT KEY: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX). Activation: Instant online activation, tied to your Microsoft account. License Type: Retail, lifetime warranty, no regional restrictions. Supports: All languages, x86/x64/ARM architectures, even MacOS with Parallels.