Aug 12, 2011 13:31 GMT  ·  By

Users of some Windows 7 Service Pack 1 (SP1) computers can experience issues related to the way in which the operating system reports the quantity of RAM installed on the machine. Microsoft has confirmed the problem, and revealed that Windows Server 2008 R2 SP1 is also affected.

According to the software giant, the glitch is associated with PCs sporting chipsets with integrated Graphics Processing Units (GPUs).

Such chipsets need to reserve a portion of the memory installed, and allocate it to the GPU, since the integrated component doesn’t come with RAM of its own. However, if the integrated GPU doesn’t even support Aperture memory-mapped I/O (MMIO) range, then Windows 7 SP1 will incorrectly report the RAM installed.

“This issue occurs because Windows locks the primary surface, and then uses the CpuTranslatedAddress address to shadow the primary surface. Therefore, the primary surface is exclusively allocated from a segment of memory that is visible to the CPU,” Microsoft said.

“Most Integrated GPUs have an Aperture MMIO range. In this situation, Windows must reserve memory at startup, and expose the reserved memory as a dedicated memory segment. By default, a primary surface must be located in a segment of memory that is visible to the CPU. This is a segment of linear memory space that the GPU has exposed by using a CpuTranslatedAddress address,” the company explained.

The software giant revealed that computers with Intel GMA 3600 GPUs are among the PCs on which Windows 7 SP1 will actually report less memory than what’s actually there.

The Redmond company has already produced a hotfix designed to resolve this issue, but customers will need to manually download it and deploy it themselves.

“After you install this hotfix, Windows 7 and Windows Server 2008 R2 support primary surfaces for GPUs that do not have an Aperture MMIO range,” Microsoft said.

Windows 7 SP1 RTM and Windows Server 2008 R2 SP1 RTM are available for download here.