what is this error all about when installing half life?

[acidvoodoo]

_INS5176 performed an illegal operation and will be shut down, details=


_INS5176 caused an invalid page fault in
module ZDATAI51.DLL at 0137:10003ebf.
Registers:
EAX=0000000b CS=0137 EIP=10003ebf EFLGS=00010287
EBX=ffff72bb SS=013f ESP=006bf5ac EBP=00bf1000
ECX=00be8000 DS=013f ESI=00000045 FS=3237
EDX=0000045b ES=013f EDI=00bf0fbb GS=0000
Bytes at CS:EIP:
88 4d 00 45 47 4b 75 f6 8b 7c 24 18 eb 19 33 c9
Stack dump:
00000001 00cf0420 00cf0ed0 1000de50 000052d8 00007dc1 00be00bd 0000007f 1000358d 00000000 0000001f 1000efc0 1000e338 00cf0420 1000de50 00be0079


any idea how to fix this?

amd k6-2 450
128mb SDRAM
voodoo 3 agp
win 95 b

this copy has installed fine before by the way :S