Speeding issue is a common thing not just with Malwarebytes Helpline Number but with other antivirus system. When you have schedule antivirus scanning process and at the same time you are using other programs on your computer, your computer is bound to show slow speed. More Info :- http://www.liveantivirushelp.com/blog/2017/09/27/how-to-fix-malwarebytes-anti-malware-error-383/