David Roberts, chairman of Tif, the forum for large corporate IT users, said many large organisations had already made strategic decisions about Microsoft following the changes it made to its software licensing terms.
The software giant's market domination and the reduced choice of suppliers only became an issue for users when it affected value for money, he added.
Bob Griffiths, national secretary of the Society of IT Management (Socitm), the local government IT directors' organisation, agreed. The cumulative impact of legal trials, ongoing security problems and the changes in its licensing regime had raised awareness of alternatives to Microsoft, he said.
"We hope this ruling encourages Microsoft to make its products more competitive, and more secure," said Griffiths. "They've got to do it because the open source bandwagon has begun to roll."
According to interim IT director Colin Beveridge, users tempted to criticise Microsoft should remember they put the company where it is today.
"We wanted easy control of the desktop," said Beveridge. "The situation in the '80s was anarchic and Microsoft brought standardisation."
Microsoft has already begun to start opening up its source code - a key point in the antitrust case, he added. Pointing to the adoption of XML in the Office desktop suite, Beveridge said, "I think that's more significant than the legal shenanigans in the US."