STOP 0xC4 may occur in tcpipreg.sys following a reboot after Driver Verifier is enabled on Windows 7 SP1 or Windows Server 2008 R2 SP1


After enabling Driver Verifier (Verifier.exe) and restarting the machine, the following STOP error may occur during the "Applying Computer Settings" startup phase:

   *** STOP: 0x000000C4 (0x0000000000000000,0x0000000000000000,0x0000000000000000,0x0000000000000000)


When Driver Verifier (Verifier.exe) is enabled on the tcpipreg.sys driver, the STOP 0xC4 occurs following a NULL length memory allocation.


There are two possible resolutions:

1. Disable Driver Verifier        

a. Boot the machine into Safe Mode

b. Run verifier.exe and choose "Delete existing settings"


2. Remove the registry key that can cause the null-byte allocation (verifier can remain enabled)

a. Boot the machine into Safe Mode

b. Run regedt32.exe

c. Find the following registry key, and if the Data value is empty, remove the registry key.


Name: IPAddress

NOTE: If the Data is non-NULL, then this is not the cause of this STOP error and the IPAddress registry value should not be deleted. If IPAddress shows no Data value, then delete the IPAddress entry and restart the machine.

More Information

This problem has only been observed after the machine's TCP/IP configuration has been changed from a static IP address to a dynamic address with DHCP, which leaves an empty value for the IPAddress registry key for the network interface.

NOTE: If the computer is configured to reboot automatically following a failure (within Computer / Properties / Advanced system settings / Startup and Recovery Settings / Automatically Restart checkbox enabled), the STOP error may never appear on the display before the restart occurs. Instead, the machine will restart and display the option for booting Windows into Safe mode.  If no dump file is created, the only indication of the failure may be a Critical error logged to the System Event log:

   Event ID: 41
   Source:   Kernel-Power
   General:  The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped
             responding, crashed, or lost power unexpectedly.