[msbuy.ru]

Здравствуйте.

Если вопрос еще актуален, то, возможно, вам будет интересна статья - http://support.microsoft.com/kb/2021579/en-us

В статье, среди прочего, сказано:

Question: Can you convert the evaluation version to a full version?
Answer: Although this conversion is not blocked, we do not support an upgrade from an evaluation version to a full version or changing the product key to a full version key. To upgrade to a full version, you must install non-evaluation media. If you change the product key to Full Version, the visual evaluation references in Winver and as displayed in Slmgr /DLV output are removed, but the WLMS service remains on the system and the media retains its evaluation status.