Best way to handle UNC network share time out under Windows 7?

I believe the underlying protocol for UNC shares is Server Message Block (SMB) (SMB2 in Win Vista and later). Take a look at the SESSTIMEOUT registry setting. It sounds related and defaults to 45 seconds,

Microsoft Support - SESSTIMEOUT Information

I'm having trouble reproducing this issue to test modifying this value. Can you add additional information about how to reproduce this problem? How do you make a UNC share unavailable? Remove the system from the network? I've tried an unknown host and an unknown share name, but both requests fail fairly quickly in Windows Explorer.