Malwarebytes for Windows protects your PC from advanced malware and ransomware, replacing antivirus software with technologies designed to prevent today's online threats.

Steps to reinstall Malwarebytes Premium

• Click on Start and select Control Panel
• Open Add/Remove Programs
• Uninstall Malwarebytes' Anti-Malware
• Restart your computer very important
• Download and run mbam-clean.exe
• It will ask to restart your computer, please allow it to do so very important
• After the computer restarts, temporarily disable your Anti-Virus and install the latest version of Malwarebytes' Anti-Malware

• Note:

  • You will need to reactivate the program using the license you were sent via email if using the Pro version
  • Launch the program and set the Protection and Registration. Then go to the UPDATE tab if not done during installation and check for updates.

  Restart the computer again and verify that MBAM is in the task tray if using the Pro version. Now setup any file exclusions as may be required in your Anti-Virus/Internet-Security/Firewall applications and restart your Anti-Virus/Internet-Security applications.

You can see the detailed guides from here How to again install Malwarebytes Premium.