I thought Bitdefender would stop the popovers from Norton's and McAfee but they're still coming up. I uninstalled McAfee that came with my new laptop and there's nothing I can find that has anything to do with Norton's.
Check if the below-stated steps help:
1) Use the McAfee and Norton product uninstallers, though they will not help with fake popups, but still, to be on the safer side
McAfee uninstaller: https://download.mcafee.com/molbin/iss-loc/SupportTools/MCPR/MCPR.exe
Norton uninstaller: https://buy-download.norton.com/downloads/RnR/NLOK/NRnR.exe
2) For the removal of McAfee and Norton popups, kindly check their respective support websites, as stated below:
McAfee:
https://www.mcafee.com/support/s/article/000001899?language=en_US
https://www.mcafee.com/learn/how-to-stop-the-popups/
Norton:
https://support.norton.com/sp/en/us/threat-removal-solutions/current/solutions/v122764455
https://support.norton.com/sp/en/uk/home/current/solutions/kb20100811171926EN
3) Open the Run command and execute the following commands one by one:
temp – delete all the files in the folder.
%temp% – delete all the files in the folder.
prefetch – delete all the files in the folder.
4) Run Disk Cleanup using this guide: https://support.microsoft.com/en-us/windows/disk-cleanup-in-windows-8a96ff42-5751-39ad-23d6-434b4d5b9a68
5) Reset the Windows host file to default. You can find instructions here: https://support.microsoft.com/en-us/topic/how-to-reset-the-hosts-file-back-to-the-default-c2a43f9d-e176-c6f3-e4ef-3500277a6dae
6) Also, check the link provided by Bitdefender Support: https://www.bitdefender.com/consumer/support/answer/2574/
Additionally, you can also check the links below that may provide further assistance.
for McAfee Popups
https://malwaretips.com/blogs/remove-fake-mcafee-pop-up-virus/
https://malwaretips.com/blogs/remove-mcafee-viruses-confirmed/
for Norton Popups:
https://malwaretips.com/blogs/remove-fake-norton-popup-virus/
https://malwaretips.com/blogs/remove-norton-viruses-detected/
Regards