Ubuntu Gnome 14.04 LTS slow internet Problem

Method 1:
Disable IPv6 If your internet is working Slow . I recommend before you change any file ,please keep a backup.

To do this open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

sudo gedit /etc/sysctl.conf

Now add these lines at the end of file:

# IPv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1 

Now Save sysctl.conf file and close. 

Enter following command to restart sysctrl settings:

sudo sysctl -p

Method 2:
open your terminal and type:

sudo gedit /etc/nsswitch.conf

Find the following line :
hosts:          files myhostname mdns4_minimal [NOTFOUND=return] dns

replace the the line with the following:

hosts:          files dns

save the file before you exit.