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Product key format reference
Every Microsoft product key is 25 characters in 5 groups. Here's how to tell what you've got.
Standard format
XXXXX-XXXXX-XXXXX-XXXXX-XXXXX — uppercase A–Z and 0–9, no I, O or special characters.
Identifier table
| Product | Typical prefix | Edition hint |
|---|---|---|
| Windows 11 Home | X4XYW / 8K7N | Retail / OEM |
| Windows 11 Pro | VK7JG | Retail Pro |
| Office 2024 | N9KFC / 2WHHK | Home & Student |
| Microsoft 365 | — | Sign in at office.com/setup |
| Windows Server 2025 | D764K | Standard |
| Windows Server 2025 DC | WMDGN | Datacenter |
Before you click any download
If a URL above does not start with microsoft.com, learn.microsoft.com or aka.ms, stop and report it to research@licensevault.net. Counterfeit ISOs are the single largest source of activation tickets we see — always check the SHA-256 hash Microsoft publishes alongside its download.
More resources
Official Microsoft ISO downloads
Every link below points to a Microsoft-hosted ISO or Media Creation Tool. We don't host installers — only the keys.
Deactivate and transfer a Microsoft license
Retail keys move freely between machines as long as you deactivate the old PC first. OEM keys can't be transferred.
Activation troubleshooting reference
The 12 errors that account for 90% of support tickets — and the one-line fix for each.