Cannot Install Comodo Antivirus Error 1603

While you try to install Comodo antivirus or update the already existing version of Comodo antivirus on your computer, you may encounter the ‘Cannot install Comodo Antivirus Error 1603’. There can be many reasons for this error to occur during the installation.It may be due to an incomplete or corrupt download of the installations files, corrupted registry entry on your Windows computer, or viruses on your computer that might have corrupted or deleted your installation files. If you face the Error 1603 while installing the Comodo antivirus on your Windows computer, then try any of the given methods to solve it.

Method 1: Restoring your Windows computer:

  • Log in to your Windows computer as Administrator.
  • Click the Start menu, right-click on the 'My Computer' icon and select 'Properties' option.
  • Select the System Protection option in the next window.
  • Here, you can create a restore point of your computer with the current snapshot. For this click on the Create button, enter the name for the current restore point, and click create.
  • Now, click the Start menu > All Programs > Accessories > System Restore.
  • Then select a restore point, which is the most recent one, except the one you created just now.
  • Now, click the Next button.
  • Once your computer is restored, try installing the Comodo antivirus software once again.

Method 2: Closing other conflicting programs:

Since the ‘Cannot install Comodo Antivirus Error 1603’ can arise due to the conflicting programs running on your computer while you install the Comodo antivirus, try to end the other conflicting programs running on your computer by going through the below steps.

  • Open the Task Manager on your computer. For this, right-click on the taskbar, select the Task Manager or press Ctrl, Alt, and Del keys together, and then select the Task Manager option.
  • In the Task Manager window, switch to the Processes tab.
  • Now, click and select the conflicting process running on your computer and click End Process.
  • After closing the conflicting programs, try to install the Comodo antivirus software on your computer.

Method 3: Reinstall Comodo antivirus:

If you are trying to update the existing Comodo antivirus version on your computer, then try to uninstall the earlier version and reinstall Comodo antivirus again. The steps to uninstall the previous version of Comodo antivirus is given below.

  • Click the Start menu and select the Control Panel option.
  • Click the Uninstall a program option from the list of options.
  • It will take you to the Uninstall window with all the programs installed on your computer being listed out.
  • Click and select the Comodo antivirus, and then click the Uninstall/Change button. 
  • Follow the instructions to uninstall Comodo antivirus from your computer.
  • Then restart your Windows computer and try installing Comodo antivirus again.


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