This book is written on hardware which are used in desk top computer. The book contains 14 chapters which have included the general construction details with pictures of mouse, keyboard, monitor, hard disk, floppy disk, CD- ROM, SMPS, motherboard, RAM chip, microprocessor and modem along with their functions and related problems and their rectification. All the external connections like monitor, mouse, keyboard, modem, speaker, printer and power with the CPU are displayed by pictures. Internal power connections from SMPS to the hard disk, floppy disk, CD-ROM and motherboard are explained and shown by pictures. Ribbon cables or data cables connections from motherboard to the hard disk, floppy disk, CD-ROM are displayed by figure. This internal and external connections help the reader to assemble his own computer.