Before installing Revit software or performing a complete uninstall, you must disable anti-virus programs.
Disabling anti-virus programs from the system tray may not be sufficient. Virus-checking programs may block certain activities that are considered to be suspicious, such as accessing the registry, and adding, removing, or updating DLL files. These activities are common when installing or removing programs.
You can often disable an anti-virus program by right-clicking the taskbar icon and selecting Disable from the shortcut menu. For more information about disabling your anti-virus software, refer to the vendor of that software.
In addition to disabling the anti-virus software, you must use the End Task feature to end the process for the anti-virus software, as follows.