start /wait MsiExec.exe /X{C40698F9-A861-4531-9F8C-FA7F8961375B} /quiet /qn
to remove the client
start /wait MsiExec.exe /X{9BC51C0F-DA8E-4370-9997-899B3435A647} /quiet /qn
to remove host update utility
You may want to check the guids - they were the same for the two machines I looked at, but can't ever tell with guids. They are in the registry uninstall information:
For 32 bit
hklm/software/microsoft/windows/currentversion/uninstall then search for vsphere
For 64 bit
hklm/software/wow6432node/microsoft/windows/currentversion/uninstall then search for vsphere
Good Luck