As greggw124 states, using regedit seems to be the best bet. There's a handy guide here:
http://www.vistax64.com/tutorials/79...e-disable.html
The msconfig option doesn't seem to be good enough - ISUSPM seems to reinstate itself even if you disable it from msconfig.
I found that editing HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run in regedit was sufficient, I did not find (or need) the 6 locations greggw124 refers to, but it appears that some of you have up to three installs of ISUSPM; I have only one. Best of luck!