Remote Shutdown

I have written a program to remotely shut down any computer on a
network, after becoming impatient with NT-only solutions.
However, on some computers while shutting down the following GPF
error message appears:

Mprexe

This program hs performed an illegal operation and will be shut
down.
If the problem persists, please contact the program vendor.

MPREXE has caused a general protection fault
in module USER.EXE at 0006:00004384.

Registers:
EAX=c0010300 CS=179f EIP=00004384 EFLGS=00000202
EBX=00000300 SS=1c5f ESP=00008c36 EBP=00008c5a
ECX=00021c5f DS=16cf ESI=00000000 FS=1c6f
EDX=816071a0 ES=015f EDI=00000000 GS=0000

Bytes at CS:EIP:
c4 1f 26 8b 5f 02 8b 47 02 89 46 fe 80 66 06 fd

Stack dump:
000016cf 00000000 17bf0000 1c571c5f 00000002
29280002 011c0002 00021c5f 00000000 12818ca8
0022178f 00000001 00000000 00000000 31d81c5f
00000002

This message seems to appear randomly, and only appears if the
computer is at the network logon screen. If you close this error
message sometimes the computer continues shutting down,
sometimes it doesn't. I have been unable to pinpoint the cause
of this problem or any solution.