Brother DCP-8155DN - Manual (Page 136)

Firewall settings (For Network users)
128
7
Windows Vista
®
users
7
a
Click the button, Control Panel, Network and Internet, Windows Firewall and click
Change settings.
b When the User Account Control screen appears, do the following.
 For users who have administrator rights: Click Continue.
 For users who do not have administrator rights: Enter the administrator password and click OK.
c
Make sure that Windows Firewall Settings on the General tab is set to On.