Backup glitch warning for Windows Server 2003 users

Microsoft is working to solve an incompatibility issue that prevents backups made with Windows Server 2003 from being read on previous versions of Windows.

The software giant's latest operating system saves data to tape using a slightly different format than earlier versions of Windows, a Microsoft representative said on Thursday. While older tapes can be read by Windows Server 2003, the opposite isn't true for the new OS.

A patch will be finished soon, a company representative told silicon.com sister site CNET News.com.

The issue affects only the backup utility called NTBackup.exe, which is included with the Windows operating systems. Third-party backup software apparently is not affected, said Brian Bergin, president of Boone, North Carolina-based technology consultancy Terabyte Computers, which was the first to identify the issue.

Bergin said the issue is still serious, however. He initially had urged his clients to use the NTBackup program for guarding data because it had worked well and came free with the server software. But the discovery of the flaw has tempered his enthusiasm.

"I want to make sure that a tape that I have made will work on any modern version of Windows," Bergin said.

Many of his clients live in a region known for its frequent lightening strikes and power surges. He requires his customers to sign a contract saying they'll conscientiously back up data. Bergin originally told Microsoft about the glitch a month ago, and although the company didn't see it as a problem then, they do now, he said.

"Tapes are more important than homeowner's insurance," he said. "You can have all the insurance in the world but it's not going to replace your data."

Launched in late April, Windows Server 2003 is Microsoft's server operating system for corporations. While the software uses the same Microsoft Tape Format as previous versions, NTBackup.exe writes 64KB blocks to the tape. Previous versions - in Windows XP Pro, Window 2000 and Windows NT4 - use 32KB blocks.

Robert Lemos writes for CNET News.com.