File encryption solution for network share

Solution 1:

Do the files need to be encrypted, or do you need to keep unauthorized people out? These are two distinct requirements.

I'd consider using a system level encryption on the files, on the Server 2008 computer, BitLocker might work well. Then use IPSec for encrypting LAN traffic. And just use normal access controls for authorization.

Solution 2:

EFS is the way to go: http://wikipedia.org/wiki/Encrypting_File_System

You can allow several users the access to the encrypted files (ie. Windows will encrypt/decrypt the files on the fly for them)

Works very well on Win7 / Windows 2008.