Perfect, support is really fast. 5 min tops
Thanks you!

I tried to put a key and it told me that it was already in use, I sent an email and they solved it in less than 5 minutes, excellent service!

Worked first time no issues.

Had a problem with activation key but solved telephonically. Fast and reliable. A++

There's a message here that says you can't upgrade from Home version to Pro with this key.
I managed to upgrade from Home to Pro. Here're the steps

* Type in "cmd" > run as administrator.
* Type "slrmgr /upd"
* Go to "settings" > "accounts" > login as local account.
* Change the product key.
* You may need to type in the product key again if it says something about the hardware has changed.