Setting bigger OS cache on Windows server

Hello,

I found such note in wiki of Postgresql
(http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server ):
Note that on Windows (and on PostgreSQL versions before 8.1), large values
for shared_buffers aren't as effective, and you may find better results
keeping it relatively low and using the OS cache more instead.

Can anyone tell how OS cache should be increased on windows server?


thx
Lukas