You don't need it. There is no system file called system32.exe. What you should do is go to the start menu, then run. Type msconfig and then enter.
Go to the startup tab and then uncheck the item that has the system32.exe file on it. But only remove that check mark. If you uncheck anything else, your computer might not boot anymore.
Windows is just trying to start the virus file at boot. You just need to remove the link to that file.