Almost 60% of people have a computer at home, according to interviews with 2,180 people by market research firm TNS, which conducted the research on behalf of the BCS. Just over 30% can use a PC at work and 12% use one in a library or college.
More than 35% are "very confident" users, 24% are "confident", and 53% say they can correct basic problems.
Even so, 53% find computer technology complicated, and 45% feel left behind by technology advances.
The main uses are the web, mentioned by 73%, word processing (68%) and e-mail (68%).
Positive attitudes are reflected in the findings that 82% of people agree that computers are beneficial to society, and 57% have shop-ped online. This makes shopping second only to research and fact finding (75%) as the main use of the web. Other uses are looking at news and favourite sites (53%), learning (44%), games (32%), chatrooms and dating (21%), and specialist forums (20%).
The BCS said concerns that such applications were turning people into PC junkies were dispelled by the finding that only 34% of those questioned use their computer for more than five hours a week.
But despite the positive overall view, 72% of people are concerned about the amount of porn on the web and only 32% have confidence in the security of the internet for financial transactions.
More worrying, the BCS said, was the fact that 26% of people have no access to a PC at all. "This highlights the significant proportion of adults who are in danger of being marginalised as the government gears society up for the information age," said BCS chief executive David Clarke.
"It is clear that not everyone is experiencing the benefits of computing, despite the government's aim to ensure every home has access to a PC. This area must be addressed. We see it as essential that all of society is able to use a computer with the same confidence as the telephone."
Privacy issues arising from the finding that 31% of people make personal use of the internet at work were raised by analyst firm Butler Group in a commentary on the survey.
"If these workers need to access government services, their personal details are exposed to the organisation," said Butler researcher Alan Lawson.
"The delivery of government services is something that organisations will have to incorporate into their security policies, even if only in terms of defining whether employees should be allowed to make such contacts. This poses a risk of discrimination against staff who are denied access, and also a risk if sensitive data is stolen using corporate resource."