Our Norton Antivirus (auto-protect) at start-up either is disabled or will not start. what might be

i keep setting it to start at start-up, but once in a while at a restart, i find it has been disabled or part of it locks up and won't start (usually CCapp, event log-warnings). we accepted changes for this program,but the anti-virus (auto-protect) just won't load, even manually. other times, i find that in Options, the auto-protect at start-up has been unchecked. i ran the anti-virus in both regular and safe mode and no viruses are found. what can be causing this otherwise? thanks.

Our Norton Antivirus (auto-protect) at start-up either is disabled or will not start. what might be doing it?aurora

I'll disagree with 1969. No need to uninstall Norton, it's a fine product. While some may say it's not the best, it's certainly better than AVG (I work in the industry, and I don't work for either company). It is possible that Norton could be corrupted, or causing it's own issues. I'd try two things:

1 - go to a free system scanner. Trend Micro's is probably the easiest to use. It's called housecall and you can find it at antivirus.com.

2 - if housecall doesn't find anything (or if it does and your system still isn't operating properly), reinstall Norton. You didn't mention what version you had and if you downloaded it or if you bought the physical media. Hopefully you can get a copy of the install media. If you downloaded and no longer have the install media, it may be worth a phone call / email to Symantec, they may be able to help you out.