garima8:
Hello and welcome to the forums
The taskbar (auto-launcher) at the top of the screen as well as the themes you are talking about are all part of the laptop manufacturer's preinstalled software. I would have thought that if you either used the disc(s) provided by the manufacturer or the recovery partition on the hard drive (often provided by the manufacturer) then everything would have been reset to factory defaults, including all of the pre-installed software, which a lot of people spend hours getting rid of to relieve some of the bloat to the system, but evidently you either didn't do your re-install that way or I'm mistaken. Try visiting the manufacturer's website for your specific computer and see what they have available...