Resource center
Microsoft software resources
Official ISO downloads, product-key format references, deactivation walkthroughs and an activation-error lookup table.
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.
Product key format reference
Every Microsoft product key is 25 characters in 5 groups. Here's how to tell what you've got.
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.