The !idt extension displays the interrupt service routines (ISRs) for a specified interrupt dispatch table (IDT).

!idt IDT 
!idt [-a] 
!idt -? 


Specifies the IDT to display.

When IDT is not specified, the debugger displays the IDTs of all processors on the target computer in an abbreviated format. If -a is specified, the ISRs for each IDT are also displayed.

Displays help for this extension in the Debugger Command window.


Windows 2000


Windows XP and later


This extension command can only be used with an x64-based or x86-based target computer.

Additional Information

For information about ISRs and IDTs, see the Windows Driver Kit (WDK) documentation and Microsoft Windows Internals by Mark Russinovich and David Solomon. (These resources may not be available in some languages and countries.)

For more information about how to display the interrupt vector tables on an Itanium target computer, see !ivt.


Here is an example of the output from this extension:

0: kd> !idt

Dumping IDT:

37:806ba78c hal!PicSpuriousService37
3d:806bbc90 hal!HalpApcInterrupt
41:806bbb04 hal!HalpDispatchInterrupt
50:806ba864 hal!HalpApicRebootService
63:8641376c VIDEOPRT!pVideoPortInterrupt (KINTERRUPT 86413730)
73:862aa044 portcls!CInterruptSyncServiceRoutine (KINTERRUPT 862aa008)
82:86594314 atapi!IdePortInterrupt (KINTERRUPT 865942d8)
83:86591bec SCSIPORT!ScsiPortInterrupt (KINTERRUPT 86591bb0)
92:862b53dc serial!SerialCIsrSw (KINTERRUPT 862b53a0)
93:86435844 i8042prt!I8042KeyboardInterruptService (KINTERRUPT 86435808)
a3:863b366c i8042prt!I8042MouseInterruptService (KINTERRUPT 863b3630)
a4:8636bbec USBPORT!USBPORT_InterruptService (KINTERRUPT 8636bbb0)
b1:86585bec ACPI!ACPIInterruptServiceRoutine (KINTERRUPT 86585bb0)
b2:863c0524 serial!SerialCIsrSw (KINTERRUPT 863c04e8)
b4:86391a54 NDIS!ndisMIsr (KINTERRUPT 86391a18)
         USBPORT!USBPORT_InterruptService (KINTERRUPT 863ae890)
c1:806ba9d0 hal!HalpBroadcastCallService
d1:806b9dd4 hal!HalpClockInterrupt
e1:806baf30 hal!HalpIpiHandler
e3:806baca8 hal!HalpLocalApicErrorService
fd:806bb460 hal!HalpProfileInterrupt