If all these ways can't work, next is the easiest.
1.Click Computer on your desktable and right click Disk C to select Properties.
2.Click Disk Cleanup, you'll see a window just as right, this process need some minutes.
3.Under Disk Cleanup there are Files to delete, tick the files you don't need to free pc space, finally click OK.
"Windows Update" is a module which used for upgrading the windows system, with it, we can upgrade the system, expand the system functions, make our system more supportive for softwares and hardwares, and keep a more stable system environment. Follow steps given as below, it is easy to install windows update.
1.Click Start button at the left corner of screen, and click Control Panel:
2.Click the option of Windows Update on new opened window:
3.After step 2, a new window - Windows Update will be opened, and click on Install updates
After all above steps finished, the process of installing windows update is completed.