This is going to be down to the new vs the old AV – most AV clients will automatically uninstall the competitors AV products
Even if you are installing new version of AV software, it is recomended to uninstall previous version. It might cause problems during the installation of new AV product or even uncompletted installation. The working AV software might see new software as virus or something else that it should prevent of working on the PC.
Don’t forget to stop AV monitor before you uninstall it or you might have problems that software could not be uninstalled.
last time from what i saw, there was a pc with 2 antivirus and due to that it could not even start up as there was issues with it…so after removing 1 antivirus, everything was back to normal
If you have SCCM, I would suggest you having them run a script uninstalling the old antivirus and doing a reboot. Once that is done, depending on how many clients you have, you can either do the install the same night or, if the install does not require a reboot, do it during working hours and the customer will never know.