According to MS Connect, this doesn’t happen. People have reported it, however, in VS 2010, 2012, and I’ve experienced the problems in VS 2013. It’s also listed at this StackOverflow question: http://connect.microsoft.com/VisualStudio/feedback/details/768230/slow-running-in-test-runner

I’ve now added this handy PowerShell command to my “initialize a new machine” setup PowerShell script:

# Disable NetBios over TCP/IP on all interfaces
# to prevent weird Visual Studio slowdowns during unit tests
Get-ChildItem hklm:system/currentcontrolset/services/netbt/parameters/interfaces | foreach{ $item = $_; Set-ItemProperty -Path ($item.ToString().Replace(“HKEY_LOCAL_MACHINE”, “hklm:”)) -Name NetbiosOptions -Type DWord -Value 2 -ea “SilentlyContinue” }