Norton Product Tamper Protection
(included in Norton 2006 and later products) is a security feature enabled by default that prevents outside programs (unknown, suspicious, or threatening applications) from making changes to the Norton software. NPTP protects NAV processes so other processes cannot access them (inject code or modify thread execution), it doesn't matter that current user has permission on them he won't be able to access Norton Anti-virus processes. This security feature can prevent Windows System Restore from changing Norton files, resulting in a "Restoration Incomplete" message and you may need to Temporarily turn off Norton Product Tamper Protection
Disabling your anti-virus programs is sometimes necessary when using specialized tools in order to ensure they do not interfere with the fixes they are designed to perform. It is also necessary to prevent the detection of those tools as a threat by the anti-virus which may attempt to remove them. If you are following instructions to disable a Norton product in order to receive assistance with malware removal, it would not hurt to disable this feature as well. Most security fix tools do not modify an anti-virus program but this feature may detect certain actions by the fix tool as suspicious and prevent it from working properly.