After getting an earful from IT professionals on the delayed release of Vista SP1, Microsoft said Monday it would make the software available this month to some customers.

Volume-licensing customers will get the English version of the software at the end of this week, Mike Nash, corporate vice president for Windows product management, announced on the Vista Team blog. Nash said other languages would follow but did not give a time frame.

Later this month, the service pack will be made available to MSDN and TechNet Plus subscribers, many of whom lashed out at Microsoft on its TechNet Plus blog with venomous comments. Nash did not provide an exact date. Customers who participated in the Vista SP1 beta were shipped the SP1 bits last Friday.

Nash also said that the timing for broad availability would not change from the original, mid-March target. Microsoft was reacting to an outpouring of criticism for announcing on Feb. 4 the release-to-manufacturing (RTM) of Vista SP1 but with the caveat that the software would not be available until March. Not only did people complain, but they also pirated copies of the service pack that began showing up on file-sharing sites; and frustrated users were downloading the software to get started on testing.

Microsoft said the disconnect between announcing the RTM of SP1 on Feb. 4 and the mid-March availability date was caused by issues with some device drivers that lose features when the service pack is installed. The device driver issue was uncovered by beta testers, who found that after the service pack was installed, certain drivers didn't work and the corresponding devices would not operate.

The issue is not one of compatibility, according to Microsoft, but the fact that the drivers do not follow driver-installation guidelines. The problem can be solved by uninstalling and reinstalling the affected device once SP1 is loaded. Microsoft said it would work to clear up the problem for good before it sends the software to volume-licensing customers or posts it to Windows Update for manual download.

Once the plan was announced, a virtual chorus of boos broke out on the Internet, with many IT pros slamming Microsoft for its decision and threatening to cancel MSDN and TechNet subscriptions. The delay also fostered questions about how deep the problem ran. Microsoft last week said it was not releasing details on the number of drivers affected or which ones they were.