Microsoft warned that testers of Windows 7 could come across data-corruption issues on various machines including computers from Lenovo and HP. The Redmond company revealed that the problem was associated with the Beta Build 7000 of Windows 7, but said nothing about any superseding development milestones such as Windows 7 Build 7048, 7057 or the more recently leaked Build 7068. According to the software giant at fault are the Offline Files service and the Client-Side Caching (CSC) driver, which fail to play nice together. Users running Windows 7 on Lenovo T60p, on Lenovo T61p, and on HP portable machines are at risk of having their data corrupted.

“Consider the following scenario. You have a computer that is running Windows 7 Beta. The Offline Files service and the Client-Side Caching (CSC) driver are enabled on the computer. In this scenario, you may encounter a data-corruption issue. This issue affects not only the files that are made available offline in the CSC database but also other files that may reside on the hard disk. For example, when your computer comes out of hibernation, the ChkDsk.exe tool may open and report a data-corruption error,” Microsoft explained.

Both the 32-bit and the 64-bit variants of Windows 7 Beta Build 7000 were affected, the Redmond company informed. Microsoft is currently offering a hotfix designed to resolve the issue, but underlined that users had to be running Windows 7 Beta in order to apply the fix.

“The data-corruption issue occurs because of interaction between the Offline Files component and certain storage drivers. These include the following Intel storage drivers: Iastor.sys; Iastorv.sys. These storage drivers are frequently found on the Lenovo T60p, on the Lenovo T61p, and on some HP portable computers,” the software giant added.