lol this should be easy..
press ctrl+alt+delete and open task manager. go to the processes tab. find the process that is related to install.exe and if its running in that tab, click it and then click end process.
the process SHOULD be the driver's EXE name, or if you want to remove install.exe it should be called install.exe in the processes menu. find the process and end it in order to do anything with it.
if you dont find the file in this processes menu thingy, then i dont know what to tell ya.
good luck pal