Anaconda-Navigator desktop launcher fails to start application

It seems like the .bashrc environment fails to load with your desktop launcher. That is why you need to manually specify the $PATH in the command that you want to execute. Try editing your desktop file (or create a new Anaconda.desktop file, if you have deleted the old one) with the following content.

[Desktop Entry]
Version=1.0
Type=Application
Name=Anaconda-Navigator
GenericName=Anaconda
Comment=Scientific PYthon Development EnviRonment - Python3
Exec=bash -c 'export PATH="/home/meghana/anaconda3/bin:$PATH" && /home/meghana/anaconda3/bin/anaconda-navigator'
Categories=Development;Science;IDE;Qt;Education;
Icon=spyder3
Terminal=false
StartupNotify=true
MimeType=text/x-python;

Did you notice the difference? Read this article on the anatomy of a .desktop file to learn more.

In order to add the application to your applications menu, simply copy the desktop file to /usr/share/applications. In order to do so, fire up a terminal and navigate to the directory where your desktop file is located, then type in the following command.

sudo cp Anaconda.desktop /usr/share/applications

Obviously, you have to replace the name Anaconda above by whatever name you have given to your desktop file. Hope this helps.

Cheers!