Windows network files are available to any user who has access to the shared network drive. If you want to prohibit edits to the Excel file on the network, Excel includes "Read-Only" protection ...
I have a client who has a computer running Windows 7 Pro 64 bit, and he uses Office 2010. His computer is a nice Core 2 Quad machine with 4 GB of RAM. All of his documents are stored on a server ...