Install msizap.exe by installing the SDK package https://www.microsoft.com/en-us/download/details.aspx?id=3138.
Run msizap to clean up temporary files
Discover how many people are logged on:
Download Systernals: https://technet.microsoft.com/en-us/sysinternals/bb842062.aspx
PSEXEC \\servername NET SESSION | FIND /C “\\”