Some media and storage devices can cause crashes of computers running the latest iteration of the Windows client, Microsoft informed.
The Redmond company did not offer a specific list of hardware products that have problems playing nice with Windows 7, but the software giant did deliver a few details.
Not only Windows 7 computers are impacted by this issue, but also Windows Server 2008 R2 machines.
According to reports from users, the crashes are associated with freshly installed third-party applications designed to be used in concert with devices relying on multiple transport Media Transfer Protocol (MTP) or on the Windows Portable Device (WPD).
Microsoft explained that Windows 7 PCs will crash when MTP or WPD devices are connected for the first time.
Customers revealed that they received the following stop error message: “STOP: 0x00000001 (parameter1, parameter2, parameter3, parameter4) APC_INDEX_MISMATCH.”
Microsoft did indicate that the stop error message parameters may vary from computer to computer, and that not all Stop 0x00000001 can be associated with the issue described above.
“This issue occurs because of a race condition in the Compositebus.sys driver. When a MTP or WPD device connects to the computer for the first time, the composite bus enumerator detects the device and tries to install the WPD composite driver”.
“During the installation process, the third-party application may run a USB device reset command. If the reset command occurs in a certain period, the race condition occurs”.
“This certain period is after the MTP and USB driver or the MTP and IP driver is installed and before the MTP composite multiple transport driver is installed”.
“When the race condition occurs, the Compositebus.sys driver incorrectly releases a Windows Driver Foundation (WDF) lock when the Compositebus.sys drive does not have the lock”.
“The APC_INDEX_MISMATCH Stop error occurs when the release function makes the asynchronous procedure call (APC) state of the current thread inconsistent,” the software giant explained.
A fix for this problem is coming in Service Pack 1 for Windows 7 and Windows Server 2008 R2. However, considering that Windows 7 SP1 will only be released in the first half of 2011, customers affected by this specific issue can access a hotfix from Microsoft at this point in time.
“Windows Portable Devices (WPD) enables computers to communicate with attached media and storage devices. WPD provides a flexible, robust way for computers to communicate with music players, storage devices, mobile phones, cameras, and many other types of connected devices. This system supersedes both Windows Media Device Manager and Windows Image Acquisition,” Microsoft noted.
“Media Transfer Protocol (MTP) is a protocol designed for portable media devices. The primary purpose of this protocol is to provide a common protocol for exchanging data between a computer and a portable media device. This includes receiving and sending media objects and enumerating the contents and capabilities of the device,” the company said.