When I upgrade VMWare Tools in my Windows 8 virtual machines (both 32 and 64-bit), the installer first asks to stop some VMWare services, then while installing the drivers logs me off forcefully (one moment the installation progress bar is shown, the next moment I'm looking at the Windows 8 logon screen).
Edit: the request to stop VMWare services also appears on Vista and 7 (but on those the install finishes without any problems).