PRB: Windows 98: PCMCIA Devices Show Error 7 in Device Manager

ID: Q196122

The information in this article applies to:

Microsoft Win32 Device Driver Kit (DDK) for Windows 98

SYMPTOMS

PCMCIA devices that install properly under Windows 95 may fail to install under Windows 98.

The device fails to start and Device Manager shows error code 7.

CAUSE

Under Windows 98 PCMCIA IRQ sharing is enabled only by default for Modem- class devices. When Pccard.vxd's Enumerator Handler receives a CONFIG_FILTER message, it performs the following checks:

In the device's hardware registry branch, is "Class" equal to "Modem"?
In the device's software registry branch, is "EnableIRQSharing" set to a nonzero value?

If either of the above conditions is true, PCCARD allows the device to share IRQs. However, if both conditions are false and the device has an IRQ descriptor with the fIRQD_Share flag set, PCCARD fails the CONFIG_FILTER message causing Device Manager to show error code 7 (CM_PROB_FAILED_FILTER).

RESOLUTION

To explicitly enable IRQ sharing, add a registry value named "EnableIRQSharing" with a nonzero value in the device's software registry branch. For example, in an inf AddReg section you could use the following line:

   HKR,,EnableIRQSharing,1,01,00,00,00

STATUS

This behavior is by design.

Additional query words:

Keywords          : kbDDK kbWinOS98 
Version           : WINDOWS:8
Platform          : WINDOWS
Issue type        : kbprb

Last Reviewed: November 21, 1998