why the storage won't improve even after uninstallingsome applications

Question

Clearing storage space won't improve with uninstalling some applications

Answer 1

Have you emptied the recycle bin? That is the normal reason for not appearing to reclaim space after uninstalling files.

I suggest you install either CCleaner or Glary Utilities and allow them to clean up your system. That should recover space for you.

If you do not have a current AV program installed (not just Microsoft Security Essentials) then there is a strong likelihood your computer is infected by one or more viruses and they are often responsible for hard drives filling up. Many of them provide storage for illegal files.