What you experience is most probably a faulty installation as there are many people who reported the same problem. Most certainly you don't have a virus on your system. You can remove the software in several ways:
- Using the Add/Remove programs feature in Windows, but only after checking that there are no Startup items related to Norton Security Scan as it will restart the installation each time you restart your PC.
- Using RevoUninstaller in its most severe mode since it will look for hidden files and pieces of the registry that the normal uninstall does not.
- Using Norton Removal Tool, the official removal tool for Norton products.
- Using RevoUninstaller and then Norton Removal Tool as some users managed to uninstall the product only this way.
- Simply remove Norton Security Scan by deleting the NSS folder (i.e. Program Files\Norton Security Scan) and delete the scheduled scan in the Windows Scheduler (Control Panel -> Scheduled Tasks). If it comes back after you have deleted both the NSS folder and the NSS scheduled scan, then something else is installing it. It might be possible that NSS installed on your system when another software installed, like Google Pack or Adobe Shockwave.
If none of these solutions helped you, get more information about this problem by accessing the link below: