System Process... Converting From VB6?

I noticed when you kill winlongon.exe, you get a BSOD and your computer crashes. I have also noticed that a number of antiviruses including Norton and Kaspersky make their processes access denied, even to administrators! Even if you use a tool like PSKill or Process Explorer, you still can't kill them. For anyone who wants to see this for themselves, get Kaspersky antivirus and then try killing AVP.EXE from any task killing utility. It doesn't work!

I'm making an application which will limit certain processes from running on my computer until a master password has been entered, where upon the access to these processes will be unlocked. I don't want the user to be able to kill the process, but I want them to be able to use other programs (including task manger, etc). I have thought of many solutions to this, including having another process which will restart my main process whenever it is not present, but this brings forth the problem of a user simultaneously killing and then deleting both of the processes, possibly with a tool like Unlocker. I have also thought about disabling task manager, CMD and taskkill, but then I fear my program will become more like a virus than a legitimate piece of software, and also other utilities can be used which will kill processes.

My problem is that I don't want to be too constraining to the user of my application so that they are not able to use every day applications, but I don't want my application to be easy to circumvent, and thus become pointless.