Well, it might be that your computer might be infected by some virus as well that is related to e-mule. So make sure that you check everything else. Anyways here's a tip that you can try to stop the rebooting Press the WinFlag key + Pause Break key (or you can just right click on my computer and select properties) and then in the System Properties window that pop's up select the 'Advanced Tab' > Under 'Startup and Recovery' click on 'Settings' button > Then uncheck the check box that says 'Automatically Restart' and click on OK (twice for both the windows) and hopefully the problem should be solved.