On 12 August, 1981, the technology giant IBM launched the world's first personal computer system for "business, home and school use".
A starter system cost $4273 and featured 64K memory, a 160KB disk drive, ran on Microsoft's Disk Operating System (DOS) and included a keyboard and monitor.
But in those days there was no internet to surf or e-mail to look through, let alone applications for accounting, designing, watching television or listening to podcasts.
The computer retailer PC World says about 200 million computers a year are now sold worldwide.
A poll of adults found it is the technological innovation they can least live without, only 19 per cent said the same about TVs.
Keith Jones, the managing director of PC World, said the original desktop PC was a long way from the user-friendly devices we use today.
"Even for those who knew how to use them, it took time to ask the PC a question and then it would take its time to give an answer."
"But those early products sowed the seeds of a revolution that has had a transformative effect on our lives, both business and pleasure."