1) Microsoft anti virus 
Microsoft Anti-Virus (MSAV) was an antivirus program introduced by Microsoft for its MS-DOS operating system. The program first appeared in MS-DOS version 6.0 (1993 ) and last appeared in MS-DOS 6.22. The first version of the antivirus program was basic, had no inbuilt update facility (updates had to be obtained from a BBS and manually installed b...
Microsoft Anti Virus [Microsoft]