From what I can tell, if memory serves me right, you can't kill winlogon.exe via Task Manager or the taskkill app; other apps can kill it (eg Process Explorer) and doing so causes an instant reboot (ie doesn't even go through shutdown procedures).

Most of the other things will work if you're using defaults like most people (ie bootloader stored in C:).
C:\Users is only there by default in Windows Vista/7, or in XP if you've changed the Documents and Settings folder.

Not sure what you've got against those IM apps.

The two bottom lines probably won't work as %path% is usually a semicolon separated list of directories, and should cause a parse error.