Several times since July 5, my Full System virus scan has only scanned one half of the files it normally does. On a normal scan, it will list about 19,000 files as ‘skipped files’. However, when it does the 'half' scan, it skips about 130,000 files. This just started July 5. I’ve been doing daily Full System scans since June 6, when I activated my free 60 day Norton trial on a brand new computer. It doesn’t do it every time I scan, but lately it is doing it more often than not. Anyone else having this problem?
Rubybear9
Hi Rubybear9,
This sounds like normal behavior. In order to improve scan times, Norton will skip any files that were found to be clean in an earlier scan, as long as no new Virus Definitions update has been downloaded by LiveUpdate in the meantime. There are usually one to three signature updates released each day, so iIf you are scanning frequently it is quite possible that you are rescanning with the same definitions used in a previous scan, and therefore all safe files are being skipped. When a new signature update is received, all previously skipped files will be rescanned in order to look for the newest known threats, and your scanned file count will again be higher.
Running a Full System Scan daily is not necessary, as the Idle TIme Quick Scans, which run after every definitions file update, will detect active threats on your machine. These scans look for any malware that is either running or is capable of running. The Full System Scans, on the other hand, look in other areas of your system to find threats that may be present but do not run - i.e. dormant threats. The current recommendation for Full System Scans on a symptom-free system is monthly, although some people still feel more comfortable with a weekly scan.
Thanks for the comprehensive answer! I've never used Norton before, I had Avast! free on my old computer. With that, sometimes the only time viruses were detected was when I did a virus scan before turning off my computer for the night.
The only thing that makes me wonder, though, is why every day for the first 30 days it scanned the larger amount of files (300,000 vs 181,000), and the discrepancy only started happening July 5th.
Hi Rubybear9,
I am not sure why you noticed this behavior only after July 5, but you may want to discontinue the Full System Scan for a day or so to allow for new virus definitions to be received, and then run a scan to see if all files are scanned. If things are working correctly, you would expect few skipped files.