You are trying to install vSphere Update Manager on Windows Server 2012 R2 (whether it is Standard or Datacenter edition) and error appears:
This product can only be installed on Windows Server 2008 or above
In addition to this, your environment meets the following prerequisites:
- The Update Manager server requires a 64-bit Windows system.
- CPU: Intel or AMD x86 processor with two or more logical cores, each with a speed of at least 2GHz
- RAM: 2GB RAM if Update Manager and vCenter Server are on different machines
- RAM: 8GB RAM if Update Manager and vCenter Server are on the same machine
- Network: 10/100 Mbps
- Network: For best performance, use a Gigabit connection between vCenter Update Manager and the ESX/ESXi hosts
Error says that you have the wrong type of OS , but in fact you have to check is your server domain controller or not. vSphere Update manager on a Microsoft Active Directory Domain Controller is unsupported scenario.
Installing VMware vSphere Update Manager fails with the error: This product can only be installed on Windows Server 2008 or above (2078069)
vSphere 6 UM: Supported Operating Systems and Database Formats