I have had this before on my Windows 7 PC.
It happens because the launcher/patcher does not have authorization to write to the directory that the files are in.
What has worked for me:
I have to close the patcher.
I place an icon on the desktop (to make this easier as I have to do this every time).
Right click on the "NCLauncher - Shortcut" and choose the "Run as administrator" option.
Then she patches without a hitch.
I hope this helps.
p.s. make sure you close the patcher. If you "x" the screen it just sits in the tray. You have to find it in the tray, right click on it, and select "exit".
