I needed to install Microsoft Windows Server 2012 Essentials on a system. Windows Server 2012 is the server version of Windows 8 and the successor to Windows Server 2008 R2. I had the product key for Windows Server 2012, but not the media. I downloaded an ISO file for Windows Server 2012 R2 Essentials from Microsoft at Windows Server Evaluations. The evaluation version allows you to try the software for 180 days before purchase. I burned the .iso file to a DVD and started the installation of the software. When I got to the "Enter the product key to activate Windows" step, I put in the product key I had, but received the message "We couldn't verify the product key. Please check your installation media." After triple-checking the product key, I had to conclude it wasn't going to work with the latest version of the software I downloaded from Microsoft's site. Someone provided me with a link where I could download an ISO file to use with the legitimate product key, but I was concerned about the possibility of tampering with the contents of that ISO file. So I checked the MD5 and SHA-1 hashes for the ISO file with digestIT 2004, which gave me the following hashes for en_server_install_disc_windows_server_2012_essentials_x64_dvd_1022281.iso:
MD5: 5ee4c7ad57248b5e791dcfd39d9e54e3
SHA-1: 1f3fbf9cd23f864a2acc6b7a6a8e6a9eb94b5c52
I was then able to verify those hashes with postings from Server 2012 Essentials RTM (SHA-1 from October 11, 2012) and Server 2012 Essentials RTM Page 2 (MD5 and SHA-1 from December 8, 2012) postings at My Digital Life Forums , which gave me the confidence to use that .iso file for the installation of the server software, since the hashes matched ones posted for the 2012 version of the software distributed by Microsoft. Such hashes are commonly used to verify that a file is exactly the same as it was when provided by the original software developer and has not been modified.
When I installed Windows Server 2012 from the DVD I burned from that ISO file, I was able to use the product key I had.
