Question

how to maintain our computer?

Answer 1

just work on it regularly and delete the temporary files and store ur data in a single folder or a briefcase in local disks .Run the Regristryclean up scan everyday and  Remove unused programs ,Modify System Restore data ,Scan and Clean Up your Registry and Lots of things get saved on your PC that you don't need.Scan/Remove spyware because Your computer may be infected with Spyware, Adware, worms or Hidden Trojans! ,install Antispyware and run daily 
and dont let any unnecessary program that starts in the task bar during bootup.

Answer 2

we can maintain it by cleaning it everyday.We should delete the unwanted files and folders. While downloading we should be very careful that virus do not enter our computer