Microsoft's Outlook email software, the target of a new computer virus, has been banned by a Cambridge University college.
Newnham College took the step after a number of users were affected by the "Klez" virus - the most recent virus to wreak havoc among computer users. It has struck thousands in recent weeks, causing damage to machines by deleting key files.
Although Outlook is not used on most college computers, Newnham's computer officer Paul McLaughlin said many students had it on their machines, which did not have good anti-virus protection.
The decision to ban Outlook and Outlook Express stemmed from the amount of time it took to restore the computers of users affected by Klez.
Mr McLaughlin said he had just one assistant and it could take several hours to repair one PC. Cutting off users from the college network was not an option, he said.
There have been some negative reactions to the move from email users, though he said most had been happy to switch to Mulberry - a program that Cambridge's computing service helped develop - or Netscape Mail. Neither was as sophisticated as Outlook but both were less susceptible to viruses, Mr McLaughlin said.
Klez has also caused significant problems to computers at other Cambridge colleges. At Jesus College, more than 100 machines have been infected.
Mr McLaughlin said Newnham was the first to ban Outlook but he believed other colleges might follow.
Jim Levi, Microsoft education group sales manager, said the company was "very disappointed" that Newnham had decided to stop using Outlook and had offered to work with the university to help deal with the virus problem.
He said Outlook was made as secure as possible but as the most widely used email programme was the first target of hackers.
Newnham continues to use other Microsoft software such as Word and the Windows operating system.