I try to launch minecraft on the new launcher and it says that it can not download the necessary files. i tried to uninstall minecraft but nothing is working.

it starts 'downloading' and then I get this error..
Unable to save download. mn_mn.lang
when I look for more information this is what I see...
ERROR
Unable to save download. ms_my.lang
Name: ms_my.lang
URL: http://resources.download.minecraft.net/13/137cc3930a6f600c045ed5ec40bba3e628cc1d64
Error details: Attempting to move successful download to C:/Users\User\AppData\Roaming\.minecraft\assets\objects\13/137cc3930a6f600c045ed5ec40bba3e628cc1d64 The process cannot access the file because it is being used by another process
Filename on disk: 0573-bc9c-721f-eacd
Path: C:\Users\User\AppData\Local\Temp\0573-bc9c-721f-eacd
Exists: file