A partial or unsuccessful uninstall of a previous ESET security product is the leading cause of failed reinstallations. To fix this issue, you must remove all nin-ESET antivirus software and reinstall your product. It can also be caused if another company’s antivirus software conflicts with your ESET security product. Run the ESET Uninstaller if your reinstallation still fails. The ESET Uninstaller will delete all files, folders, program drivers, and registry entries left behind during a failed installation.