SEATTLE (AP) - Microsoft's newest computer operating system has survived its first month on the market without needing any security fixes.

Microsoft Corp. is plugging several security holes in a regular update Tuesday. None are aimed at Windows 7, which was released Oct. 22.

Ben Greenbaum, a researcher at the antivirus software company Symantec, says that's to be expected. He says "attackers will take more time to figure out ways of breaking into Windows 7."

One of the patches is meant to thwart attacks on networks of Windows computers. An attacker who gained access to one PC would be able to break into all the others.

Computer users can get the updates through Microsoft's automatic system, or visit microsoft.com/security.