Fix Error 0xC004F074 - KMS Activation Failed

1. Check KMS server:
   ping kms-server
   telnet kms-server 1688

2. Set KMS server:
   slmgr /skms kms.windowskms.com:1688

3. Install GVLK key:
   slmgr /ipk W269N-WFGWX-YVC9B-4J6C9-T83GX

4. Activate:
   slmgr /ato

5. Verify:
   slmgr /dli

Causes:
- Port 1688 blocked (firewall)
- DNS issue (use /skms with IP)
- Clock drift (> 5 min)
- Wrong key for Windows edition

Full guide: https://windowskms.com/windows-activation-error-0xc004f074/
GVLK keys: https://windowskms.com/kms-host-keys/