Microsoft has recently announced that several media and storage devices may be behind the crashes of computers running Windows 7. While the company didn’t list the hardware products that could be clashing with Windows 7, it did however post some details regarding the situation. According to Softpedia, both Windows 7 and Windows Server 2008 R2 computers are impacted by this issue.
Most users who encountered such a crash could generally associate it with installing some third-party application for a device relying on multiple transport Media Transfer Protocol (MTP) or on the Windows Portable Device (WPD). As Microsoft has revealed, upon the connection of a MTP or WPD device to the computer for the first time, the user will most likely reveice the following stop error message:
“STOP: 0x00000001 (parameter1, parameter2, parameter3, parameter4)
APC_INDEX_MISMATCH”
Microsoft also notes that the parameters in the Stop error message may vary depending on the configuration of the computer and not all Stop 0x00000001 error messages are caused by the same issue.
Then the company proceeded to explain why all this is happening. Apparently, the issue occurs because of a race condition in a driver called Compositebus.sys. Once a MTP or WPD device connects to the computer for the first time, the composite bus enumerator detects the device and attempts to install the driver for it. During the installation process, the third-party application may run a USB device reset command, which, if done in a certain period will lead to the race condition. The 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. Confused yet? Wait, there’s more.
“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.”
A fix for this problem will be included in Service Pack 1 for Windows 7 and Windows Server 2008 R2 which will be released in the first half of 2011, roughly. In the meantime, users who have this specific issue can already get a hotfix from Microsoft. The company warns that the hotfix is intended to correct only the problem described and will only worked if applier on systems that are experiencing the problem. To apply this hotfix, you must obviously be running Windows Server 2008 R2 or Windows 7. If you’re having this problem and would like to download the hotfix, you can find it right here.11
