Microsoft Corp. (MSFT) is winning accounts from VMWare Inc. (VMW) since launching a virtualiation product that competes with that company's products, Bob Muglia, head of that division, said Thursday.

Virtualization is software technology that allows one computer processor to do the work of several by reorganizing the way tasks are allocated. Palo Alto, Calif.-based VMware is the market leader.

Microsoft launched Hyper-V, a similar virtualization product, in June.

"We are winning against VMWare. Accounts from VMWare are switching to Microsoft, Muglia, the senior vice president for Microsoft's server and tools unit, said at a meeting for financial analysts at Microsoft's Redmond, Wash., headquarters.

VMWare, earlier this week, sharply downgraded its revenue guidance, attributing this to a worsening economic environment. At the time, the Chief Executive and Chief Financial Officer of the company, Paul Maritz and Mark Peak, said they hadn't seen any evidence Microsoft was winning accounts from VMWare.

Microsoft shares recently rose to $25.50 from the Thursday close of $25.44.