Install Anti Virus Software or Firewall or Internet security in all devices.Software will not increase the speed of the internet.I have personally experienced in use that.So you can use the latest Browser,You can also use the Torrent to upload and Downloading ...Reset the Devices and Connection,Modem ,Router and Restart the Computer everyday.It helps to Speed up the internet.Check the speed of the internet at here
Ip-details If these steps won't help to get Good speed or increase the speed ,Better you can contact the ISP they will help to fix this.