In 1965, he started work as a programmer for English Electric LEO Marconi, on the world's first business computer.
[3] When PCW's circulation was at its peak, Kewney was widely regarded as one of the UK's most influential writers and broadcasters on microcomputing technology,[1] founding and editing trade publications Microscope[citation needed] and PC Dealer, co-presenting Computer Trade Video and working as a TV presenter for five years on Thames TV's Database and Channel 4's 4 Computer Buffs before helping launch Ziff-Davis in Britain as the star columnist of PC Magazine (UK), PC Direct, Computer Life, IT Week, and ZDNet UK.
On 8 May 2006, BBC News 24 journalist Karen Bowerman interviewed Congolese job applicant Guy Goma live on air, after a producer had brought him on set, mistakenly believing him to be Kewney.
Kewney initially did not take the mix-up well and wrote a response on his blog, 'NewsWireless' in which he commented "[a]nd the fact that a few hundred thousand people in the world are now under the impression that I'm an ignoramus who knows nothing about technology or Apple or iPods, and has a very poor command of English?
[5] Kewney was diagnosed with colorectal cancer in 2009, which was found to have spread to the liver,[6][7] and wrote about it in his blog, The Hunky Mousehole.