the original Norton Antivirus 1.0 does not repair infected files or boot sectors properly. This was fixed when version 1.5 was released in June 1991, along with the addition of the option of installing multiple scan levels of the Norton Antivirus Intercept (later renamed to Norton Antivirus Auto-Protect starting off with Norton Antivirus 3.0 released in September 1993. Norton Antivirus 2.0 was released in December 1991, and introduced the feature of creating a rescue disk, which would include the partition table, CMOS settings memory information, and boot sector of a hard disk of an MS-DOS computer system. This is very handy in case a virus that its definitions do not detect, overwrite this information or move the boot sector to a different location of the hard disk. Norton Antivirus 3.0, released in September 1993, introduced a very unique feature. Unlike other antivirus software products for MS-DOS and early Windows, which will only notify you to turn off your computer, but continue anyway, Auto-Protect or the main program will scan for viruses in memory before loading themselves. If they find a virus loaded into memory, they will halt the entire computer so that you can't even perform a warm boot (Ctrl+Alt+Delete), So that you can turn off your computer from the power and turn it back on again with a clean, uninfected system disk. Most often, this can either be the rescue disk created, or the original MS-DOS system installation disk, followed by the Norton Antivirus program installation disks. This feature is the safest way to deal with any kind of virus in memory. Norton Antivirus 3.0 is also the first version for Windows 3.1. Product activation was introduced in Norton AntiVirus 2004, addressing the estimated 3.6 million counterfeit Norton products sold. An alphanumeric code is generated to identify a computer's configuration, which ties in with the product key. Users are allowed to activate their product five times with the same product key. Spyware and adware detection and removal was introduced to the 2005 version, with the tagline "Antispyware Edition". The tagline was dropped in later releases. However, Norton AntiVirus 2009 Classic does not include spyware or adware detection. The Classic edition is marketed alongside Norton AntiVirus 2009, which does include spyware and adware detection. Existing users of the 2006, 2007, 2008, and 2009 versions can upgrade to the latest 2010 version without buying a new subscription. Upgrading will preserve the