This tutorial is mainly written for Bangladeshi people

The following method will not work in LM 18/Ubuntu 16.04 or later. Follow this method of installing wvdial and using network manager instead

To install Teletalk Flash modem software in Linux Mint or Ubuntu follow the instructions below:

#1. Installing in Linux Mint 32bit/64bit & Ubuntu 32bit:

First check if ia32-libs are installed (open software manager and search for it) if you have a 64bit system. If not then install it from synaptic/software manager.

Insert your usb modem to a usb port. Then open the modem directory (it is mounted as a CD ROM). Go to the folder named "Linux". Open the archive with archive manager (double click on the file). Now extract it on your Downloads folder (or anywhere else).

Now run these codes in terminal:

cd ~/Downloads               

change the directory path accordingly if you extracted the archive in another directory other than /home/user/Downloads.

sudo ./install.sh

After some time it will finish installing and ask for any key be pressed. Press any key and it will launch the modem connection manager window. Close this window for now.

Now Go to the /usr/share/applications directory and look for Teletalk_3G. There you will find a .desktop file named Teletalk_3G.desktop. Open this file as root with a text editor:

In Linux Mint:

First open the folder as root then right click on the file and select "open with" and then text editor.

In Ubuntu:

open a terminal and give command:
sudo apt-get install gksu
gksudo gedit /usr/share/applications/Teletalk_3G.desktop

Look at the context of the file and find a line that says Exec=Teletalk_3G and change it to Exec=gksudo "Teletalk_3G"

Now you can find this Teletalk_3G entry in the menu->Internet->Teletalk 3G. Run from there and connect to internet.

N.B: It will ask for root password every time you run it.

#2. Installing in Ubuntu 64 bit:

You first need to install ia32-libs in ubuntu. If you are running Ubuntu 14.04 LTS then you won't find this in the repo. For that case run these codes:

sudo -i
dpkg --add-architecture i386
cd /etc/apt/sources.list.d
echo "deb http://old-releases.ubuntu.com/ubuntu/ raring main restricted universe multiverse" >ia32-libs-raring.list
apt-get update
apt-get install ia32-libs
rm ia32-libs-raring.list

Now you can follow the instructions for installing in Linux Mint (#1) from above.