NIS affected internet connection? Error 8506, 421

Due to a problem with NIS, I had to reinstall it, which appeared to have been done successfully, however the Live Update failed and when I tried to investigate the problem Google Chrome wouldn't open saying that there might be a Firewall or internet security issue. Norton Error 8506 421 appeared and when I tried to open the link to solve it Internet Explorer wouldn't open either. I am using Windows XP and have wireless internet which is still working on other machines in the house so it's not actually an internet problem.

Can anyone help?

I got a similar error message yesterday , 8506,422 that appeared on what looked like a valid Norton type scan window - I let it run for awhile & then just aborted it  -  it just appeared out of the blue - don't know what those error numbers indicate but my laptop is running fine , nothing funky showing up but I may do a full scan anyway .

Hi,

Here's a link to a possible solution

https://support.norton.com/sp/en/us/home/current/solutions/v80281719_EndUserProfile_en_us

Keep us posted

Thanks for your replies - unfortunately because something has happened to the internet connection I can't download the removal tool - do you think I could download on another PC then save onto memory stick?

Yes, you can and then use it fro the USB-stick.

Thanks I'll keep you updated.