WSS W2000/W4000/W5000/W8900/W12000/W16000 how to found the Winodows license key?

W2000/W4000/W5000 bundle with WSS 2012 R2 ESSENTIAL, and the license stick on the top cover.
W8900/W12000/W12000 preinstall WSS but without license key, it is need to purchase from your resller or distributor.
(The W8900/W12000/W12000 base on LSI 9200-8i have HW RAID 0 & 1 support.)

If you have the WSS license key but unable to activate, please contact with Microsoft directly and following link for your reference:
http://www.microsoft.com/licensing/existing-customers/activation-centers.aspx