How do I increase the number of system page table entries(PTEs)?

NTDEV
1

I have two NT4.0 machines, one with 256Meg and one with 512Meg. Both will
blue screen with the NO_MORE_SYSTEM_PTES error when my driver
probes/locks/and allocates MDLs for more than 188Meg of memory. I have
tried increasing the “SystemPages” registry setting above the
out-of-the-box 80,000 but it does not seem to make any difference. How
else can I increase the system page table size?
Thanks,
Doug Hoyt