This is very very frustrating. I had installed Speedfan on my computer to monitor temps and give me some fan control, but at first found it a bit confusing. So I uninstalled it and installed Intel's Desktop Utilities software.

Now I'd like to try Speedfan again, but if I start that program, Desktop Utilities throws a fit and won't work correctly anymore. I now want to get rid of Desktop Utilities, but when I try to remove the program from add/remove software, InstallShield pops up an error saying "Install can't finish when multiple users are logged on. Install will now abort."

So what is this, there's no way to get rid of this thing unless I reformat?? I can't seem to get the icon out of the system tray, either.

At the very least, I'd like for the program to NOT start when booting up.

Try starting up in Safe Mode under the Administrator account and see if this fixes your problems. Interesting ordeal you're having there, I have the Desktop Utilities installed myself simply for monitoring, no control needed atm. I may play around with it a bit just to see how it goes for me.

If u want to keep it. You can type Msconfig on run and disable it from startup items, then you can use it when you want it. Then it won’t startup when you are login in next time

disable fast user switching to uninstall completely. Control Panel -> User Accounts -> Change the way users log on or off, uncheck Fast User Switching, hit apply.
That is where your multiple users are comming from.
Better yet, do not install anything from Avocent