Disabling file cache on large files

There's just no point in trying to put large files (say, more than
100MB) in the cache. They're too big and only eat up all the other
cache, making the system extremely slow.

Still, when such files are read, Windows tries to cache those files in
memory, and I can't help thinking there must be some way to prevent this
from happening without disabling the file cache alltogether. And yes, I
know it's up to the application to open a file with cacheing disabled on
it. But what if the "application" is simply the explorer that's copying
such a file?

Of course, having 1,5GB of memory works around this problem, but in some
environments (such as ours) we can't simply upgrade each and every PC to
such amount of memory

Any help or hints?

--
Thanks,

Martijn Saly