BASIC INTRODUCTION ABOUT (HARDWARE & SOFTWARE), OS INSTALLATION (WINDOWS & LINUX), MS-DOS COMMAND & BASIC UNIX COMMAND, HARDWARE DEVICE (SMPS, RAM & ROM, HARD DISK, MOTHER BOARD, PROCESSOR), HARDWARE TROUBLESHOOTING, SYSTEM ASSEMBLING & ASSEMBLING, MAIL CONFIGURATION & MAIL BACKUP, SYSTEM IMAGE BACKUP & TYPES OF DATA BACKUP, RAID CONFIGURATION.