Some customers running those operating system versions have reported that their systems stop responding randomly. Microsoft has analyzed the issue and discovered that it will typically occur when the memory usage is high and when the Windows memory manager performs “frequent paging in and paging out actions”.

The cause is a deadlock situation int he Microsoft Filesystem Filter Manager (Fltmgr.sys).

Microsoft has released a hotfix and instructions on how to pinpoint the random freezes and lock-ups of the operating system.

The hotfix is available for download at the Microsoft Support website. Users who want to download the hotfix need to access the terms of service and fill out information on the Hotfix Request site including their email address before they can download the program to their computer system.

Microsoft sends a download link of hotfix to the email address entered in the form on the hotfix request page. This in itself is a rather complicated process; A simple download link would make it a lot easier for users to download the fix from Microsoft.

It should be noted that only users who experience freezes and responding issues should download and use the hotfix to resolve those issues on their operating system. The hotfix will eventually be included in one of the scheduled patches for the operating system.

From what I can tell, the hotfix replaces the old version of Fltmgr.sys with a new version that does not cause the issue on the operating system anymore. The fix is available for 32-bit, 64-bit and IA-64 Windows 7 and Windows Server 2008 R2 operating systems.

I have to admit that I did never experience related issue so far and I’m running Windows 7 since the beta on my main system. Did you ever experience freezes? Let me know in the comments.

Computer systems running Windows 7, or Windows Server 2008 R2, with hard drives larger than 2 Terabytes, can experience full data loss on those drives if a dump file is saved on that drive, and some data of the dump file is offset at a disk offset greater than the 2 Terabyte address of the hard disk drive.

The operating system will crash on this event, generate a Stop code error message. One or more volumes of the drive may be corrupted in this scenario, with all data on those volumes lost.

The issue occurs as well if the operating system enters into hibernation, and saves the Hiberfile.sys file at a disk offset greater than the 2 Terabyte disk offset.

Even worse, the bug may affect the operating system directly if the hard drive includes the system partition, as it will make the OS unbootable.

Microsoft’s explanation is that the crash dump disk driver cannot address more than 2 Terabytes of disk space.

This issue occurs because of the crash dump disk driver (Diskdump.sys) cannot address more than 2 terabytes of disk space.

The Diskdump.sys driver can address up to 2 to the power of 32 sectors. If the sector size is 512 bytes, the driver can address up to 2 terabytes of disk space. If the actual offset is larger than this limitation, the driver incorrectly truncates the offset and saves data to a wrong location. Therefore, one or more volumes on the disk are corrupted.

Microsoft has created a hotfix that should only be installed by users with computer systems with hard drives larger than 2 Terabytes. it is recommended to install the hotfix right away to avoid possible corruption issues. The computer needs to be restarted after applying the hotfix.

Users without hard drives larger than 2 Terabytes do not need the fix. The hotfix can be directly downloaded from the Microsoft Knowledgebase.

Check out our Microsoft Windows forum for a list of additional hotfixes that have been released by Microsoft in the past month.

My understanding is that the hotfix fixes a problem with .net applications that see high CPU usage, low framerates or jittery animations among other symptoms. The hotfix addresses the Layered Window performance. In Windows Vista the the hotfix improves the read-back of video memory to system memory while layered Windows were rendered in software emulation in Windows XP which will now use hardware acceleration to improve performance.

The hotfixes can be downloaded from Microsoft directly and require a genuine system. Click to download the hotfix for Windows Vista or Windows XP. Users who did not experience difficulties yet are asked to wait until the Service Pack 1 for Vista and the Service Pack 3 for Windows XP are released. The Service Packs will contain the hotfix.