The virus has caused extensive damage in businesses across Asia but effects in Europe and the US were largely confined to home users according to experts. CIH, which activates on the 26th of each month, is more destructive than the widely reported Melissa virus and is capable of wiping data from hard drives. Monday's variant was particularly nasty as it targeted a machine's BIOS preventing users from turning on their computers. A spokesman for Data Fellows said: "In the UK there were more cases of home users being infected but even here the numbers were in the tens rather than the hundreds." Last month's Melissa virus led many firms, including telecommunications giant Lucent, to shut down e-mail servers, but the software installed following Melissa panic saved most UK businesses from CIH attacks. Jack Clark, product manager with anti-virus software firm Network Associates agreed consumers bore the brunt of the CIH onslaught: "Individual users were more likely to be hit partly because they are more likely to run "fun" executable files and CIH has been found in a lot of these," he said. Symantec's regional director Aled Miles said the company has received over 500 calls from consumers since Monday. "200 of those had had their hard disks completely overwritten," he said. All agreed individual users are less likely to run anti-virus software: "A lot of individuals get PCs pre-installed with anti-virus software and think that covers them. It comes down to knowing about the threat and bothering to do something about it," said Clark. Miles denied it was a matter of cost, likening the purchase of anti-virus software to getting car insurance. "People don't realise the benefit until they need it," he said. "There is an element of 'it won't happen to me and anti-virus software is constantly competing with entertainment software for people's budgets," he added. One anti-virus spokesman pointed out that many firms offered free downloads for CIH. "I am not saying anti-virus companies are marvels of altruism, but when a widespread and damaging virus like CIH comes along they do give something for nothing," he said. Take me to the Melissa Virus special. A free download to detect and remove CIH is available from ZDNet Symantec Network Associates