I could not get the vSphere client to install on Windows 8.1. I rebooted and it still didn’t work. It turns out that the client requires .Net Framework 2 or 3 to install. In Windows 8.1, it is a feature that just needs to be turned on. Go to Control Panel\Programs\Turn Windows features on or off. Then, check off .NET Framework 3.5 (includes .NET 2.0 and 3.0).

Once complete, you should be able to install the client.