You might receive a Stop 0x000000D1 i.e DRIVER_IRQL_NOT_LESS_OR_EQUAL error after you enable an iSCSI Initiator data digest setting that uses CRC or that uses checksum in Windows Server 2008 R2 or in Windows 7.

This can happen because the iSCSI Initiator incorrectly processes sense data from a device after it receives a nonfatal check condition when iSCSI data digest verification is enabled. This issue usually occurs when tape devices or other non-fixed-disk SCSI devices are used.

To correct this issue you could visit KB982674 and request for a Hotfix. Apply this hotfix only to systems that are experiencing the above mentioning  problem.

Not all “0x000000D1″ Stop Errors are caused by this issue. If you are not severely affected by this problem please wait for the update from Microsoft Update.

For more information about Microsoft iSCSI Initiator Features and Components check these TechNet articles:

• Understanding Microsoft iSCSI Initiator Features and Components
• Using Microsoft iSCSI Initiator in Windows Server 2008 R2 and Windows 7.