Delete a file or folder that cannot be deleted

Download Unlocker

and use it to delete the folder / file.

Free space on windows partition - Disable Hiberfil.sys and change virtual memory partition

1. Run cccleaner and free temporary files.
You can access temp folder by : %temp% manually

2. Disable Hiberfil.sys - around 4gb of space
Easiest mother open a cmd with administrator rights and type :
powercfg.exe -h off
powercfg.exe /hibernate off

3. Move Virtual Memory to other partition :
Open System Properties - Advanced -> In Performance section select - Settings - Advanced -> Virtual Memory - Change - Set to No paging file on windows partition and the select other partition and set it to System Managed size