Known error if you try and browse to server files from Windows 7 machine
1.Try disabling auto-tuning on the windows 7/8(you should run this command in run as administrator mode)
" netsh interface tcp set global autotuning=disabled "
2.try disabling ipv6 from win7.
open regedit.exe go to the hklm>system>current control set>services>tcpip6>parameters create new dword32 value "DisabledComponents" enter the value as FFFFFFFF