Windows NT employs about 150 Stop Codes. However, you encounter the following Stop Codes most frequently. For a complete list of NT's Stop Codes, see the bugcodes.h file in the Windows NT Device Driver Kit.
IRQL_NOT_LESS_OR_EQUAL 0x0A
This code is probably the most frequently appearing code, and it usually
results from a buggy driver. The most common source of the problem is that the
Virtual Memory Manager has detected a kernel-mode component's attempt to access
pageable memory when the IRQL is Dispatch Level or higher and the memory is in
the paging file. The IRQL must be below Dispatch Level for this operation to be
legal. Look at the modules listed in the Stop Code and stack trace areas of the
screen for a possible candidate. This code can also be a side effect resulting
from a driver not shown in either area that scribbled on memory it shouldn't
have.
UNEXPECTED_KERNEL_MODE_TRAP 0x7F and KMODE_EXCEPTION_NOT_HANDLED 0x1E
These two codes also show up frequently. In this case, the Microkernel's
processor exception handler has detected that a driver or subsystem has tried to
execute an illegal processor instruction, or a software instruction that NT
cannot interpret. The cause can be a faulty memory module or a driver that has
corrupted memory. The module information on the blue screen is usually
misleading in this case, making it difficult to identify the source of the
problem.
NO_MORE_IRP_STACK_LOCATIONS 0x35
With this code, if you've added a new virus scanner or someone has accessed
a shared volume over the network for the first time on the machine, the Server
device driver can be at fault. The Server device driver constructs I/O request
packets with a slot for every device driver on the path to the disk. Sometimes
the number of I/O request packets the Server device driver allocates is
insufficient, resulting in this Stop Code. Try increasing the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ServicesLanmanServer\IrpStackSize setting to a number higher than 4 (or whatever it's
set to) and see whether the problem goes away.
INACCESSIBLE_BOOT_DEVICE 0x7B
If you see this Stop Code, NT is very early in a boot and cannot access the
disk partition that boot.ini is pointing to for the location of the system files
(where your \winnt directory resides). The disk containing that partition is
faulty, or the data on the disk or partition has become corrupt. I encountered
this code when I left an NT 4.0 distribution CD-ROM in my CD-ROM drive and
rebooted. The computer tried to boot from the CD-ROM, and NT displayed this
message when it couldn't continue. An NT repair install is worth a try, but
you'll likely have to buy a new driver or reformat, reinstall, and restore
backed-up data.