According to VMware, screen savers are not necessary for virtual machines and if they are running, they waste valuable CPU cycles.
On Windows 2008R2, you can open up Control Panel > Appearance and then select (None) from the dropdown.
Another method is to edit the registry… Click Start > Run dialog and type RegEdit.exe and click OK…
When the Registry editor is open, navigate to…
Set the ScreenSaveActive value to zero. You can learn more by visiting this VMware LINK.