Installation Failure – NAV2003

My PC is running with (Redhat 7.2 / WinXP)dual booting. After Completing installation of Nortan Antivirus 2003 in WinXP(FAT 32),restarting the OS and when I try to run the NAV2003 it results that “you must restart the system”. Again and again restarting the system, replies the same error. Then I have reinstalling the Nortan Antivirus but the same error occurs. But NDD and all other Nortan utilities are working properly. What can I do for this. please any one help me.