I'am a new ubuntu user. I install ubuntu 14.04 LTS unity distro. At first it was fast enough to work with. But as soon as I install more apps it becomes impossible to work with as it becomes so slow in case of multi-tasking. So can any one suggest a stable version of debian package that I can install ? Oh another thing, I have installed a lot of software. How can I backup them and transfer then to new OS?
Hardware specification: Intel core i3 2.66GHz, 4GB RAM, 6 GB swap memory, Dell Inspiron 15 Intel Core i3-390M 2.66GHz 15.6in Laptop