microsoft downgrade right
"If you are a VL customer, you can use your VL media and key to downgrade.
If you are not a VL customer Microsoft does not provide the media or key to downgrade.
Downgrade media and activation key must match... ie. If OEM media used to downgrade, then OEM key must be used to activate as VLK or Retail activation key would fail when activating."
How to
Telefonba:"When you talk to the person from Microsoft activations just explain that you are downgrading your Windows 8.1 Pro version to Windows 7 pro and then you read out the nine sets of six numbers and they will tell you the confirmation numbers then your Windows 7 Pro install is activated."
off:Nem lett volna egyszerűbb venni egy win 7 telepítő médiát kulccsal együtt?