With Steve Ballmer announcing the coming of Windows 7 broad test phase, Microsoft released the Betas for the next generation operating systems to MSDN and TechNet simultaneously.

Subscribers of MSDN/TechNet could already touch on the new betas from yesterday, while the public still have to wait a little longer when Redmonds reached certain hours on January 9, the time to start worldwide beta test of Windows 7.

Also available to MSDN/TechNet users are betas of Windows Server 2008 R2 and many more resources for IT Pros.

One thing to notice is this is still a beta, no matter how stable Windows 7 Beta is. A most possibly devastating bug now should be the one in Windows Media Player 12, which would permanently erase a few seconds off your MP3 files of a certain type. So please be very careful if you got a lot of MP3 files on hard disk. Back them up before you open the latest WMP, as what is suggested in the release note of Windows 7 Beta from Microsoft.

MP3 files

When MP3 files are added (either manually or automatically) to either the Windows Media Player or the Windows Media Center library, or if the file metadata is edited, several seconds of content may be permanently removed from the start of the file. This issue occurs when files contain thumbnails or other metadata of significant size before importing or editing them.

To avoid this, ensure that all MP3 files that may be accessed by a computer running Windows 7 (including those on removable media or network shares) are set to read-only. To do this, in Windows Explorer, find the files, right-click them, click the General tab, and then select the Read-only check box. Then back up all of the MP3 files prior to using Windows Media Player or Windows Media Center.

If some of your files have already been affected, you may be able to recover the data by using the Previous Versions feature. To do this, right-click the file name, click Properties, click the Previous Versions tab, and in the File Versions pane select the most recent previous version.

When public beta testing officially began, people all around the world will be able to download the ISO image of the new OS in testing phase, and claim a testing product key for product activation on the official Microsoft Windows 7 webpage.

It had been confirmed many times in Microsoft forums that the betas will be available for quite a long time but the testing product keys will be discontinued once the claimed number reached 2.5 million, usually a whopping figure for software testing but far from enough for Windows testing.

So you should be quick, or you would be late.

Windows 7 looks very promising, and it had been getting better. Let’s hope it will be shipped being a right product at the right time.