ramjet.com says:
2Gig Single Module: The 2Gig Single module can only be used in the MacBook Pro Core2 Duo, not the Core Duo.
The MacBook Pro Core2 memory maximum is 3Gigs with the installation of one 2Gig SO-DIMM, and one 1Gig SO-DIMM. If you install two 2Gig SO-DIMMs,
OSX will register 4Gigs, but will only be able to use 3Gigs. In the Core2, you may install the 2Gig SO-DIMM into either slot.
BUT will windows 64 recognize it?