Unity servers are ECS servers.
CCM servers are MCS.
Unity supported way for installing OS is using PCD Cisco Unity Platform Configuration Disc or using the Manufacturer's Guided System-Setup Utility and a Retail Windows 200X Server Disc.
http://www.cisco.com/univercd/cc/td/doc/product/voice/c_unity/unity40/inst/inst405/5ve2knf/ig_014.htm#wp1600977
Here is the link for Unity Supported Platforms List.
http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_data_sheet0900aecd802132ef.html
Remember that CCM OS is a Cisco customized Windows version. Thats one of the reason you need to install the one described above.
It may work if server is recognized by HW detection, but I think thats not supported.
