I had some issues installing an Operations Manager console on a machine. All prereqs were met, but still it failed and started rolling back during installation on Windows Server 2012R2.

Unable to add the ARP entry: Threw Exception.Type: System.ArgumentException, Exception Error Code: 0x80070057, Exception.Message: C:\Program Files\Microsoft System Center 2012 R2\Operations Manager

Somewhere in the logs I found that I had to remove the agent, so I did but that didn’t resolve. After some googling I found a topic mentioning .NET 3.5, so I removed .NET 3.5. That did solve the issue, strange as it is.

So the actionplan:

• Remove OM agent (might not be necessary)
• Remove .NET 3.5 (also removes Powershell 2.0 engine)
• Reboot
• Install OM Console
• Install .NET 3.5 / Powershell 2.0 engine)
• Install Agent
• Reboot

Hope this works for you too.