Many of our readers reported this common problem which could happen on any windows pc when you replace the old antivirus on your computer with a new one, the old one some times does not get removed completely which again will result in problems for the other new one and prevent it to get installed in first place or it might not run properly.
Following are some methods which can help you fix this problem which allows you to fix this issue if you are facing the same.
Uninstall The Old Antivirus with Add Remove or Programs Features
The best way to uninstall a antivirus is through add remove programs or programs and features and make sure you wait till the uninstall is completed and it may ask you to restart your pc as well. If there is a complete uninstall option, select that. At this point, most antivirus companies send a survey prompt. Skip the survey to save time. Once the final uninstall option is selected, the tool will automatically remove the software.
Some Antivirus Companies Gives You Uninstall Tools
Some good antivirus companies like norton has created some uninstall tools, if there is tool which a the antivirus company has already or some third party developer has created it will help you a lot. For this just search with your antivirus name + uninstall tool on google you should find it. You can read this article about 8 Antivirus Uninstall Utilities
Ensure All Files of the Antivirus Are Removed or Deleted
After uninstalling the program, it is beneficial to run a system registry cleaner. One of the best programs for this task is CCleaner which allows to clean registry and it comes for free, you can download it from here. The program is simple to use after downloading it. Follow the prompts to run the cleaner, then check the results to see if the antivirus software is completely gone.
if none of the above method work, then if you are a geek then delete all the registry keys associated with the antivirus or if you are a normal user who do not want to play with registry then you can try Revo Uninstaller