Its quite possible, that if i ll install a 4GB or 6GB version with WUBI then the
problem may not happen. This is because, i can recall when last time once i
installed ubuntu, then i installed the default 6GB option/ version of ubuntu.
And then there was no problem in updates and even i installed a lots of random
softwares also.

But this time i was experimenting with the installation and opted for 3GB
version/ option with WUBI.

Thanks for the suggestion. I will try to uninstall the current version and
reinstall again and will check if the problem gets solved or not.