Something is wrong in your install so you are going to have to remove it.

Also you dont state what O/S you are using but from another post you
mention Vista, but is it the x32 or x64?

Lastly on the compatibility options, the only ones that should be used

Run as Administrator
Disable visual themes
Disable desktop composition

Optional for some to set to run at 256 color

DO NOT set to run as another system

As a side note I did a full fresh install of ver 1.316 to fix a few issues,
and since I am running Win7 x64 and the NF program is a x32 program
I manually made sure it was installed in the proper folder "program Files (x86)"
and not the default one "Program Files" that is for x64 programs.

Since then I did not set any compatibility options and have not had as many
issues as I had before.

I dont even get to the log in screen, or the boot up screen, its just a little pop up box
that says wrong file (with no indication which file is wrong) and all you can do is click
the "ok" button lol.

Same problem, but after copying over the fixes from the downloads, it crashes at the
first loading scene.

I have exactly the same problem as show in doodoohead's link
(http://i55.tinypic.com/t66tk0.png )

I downloaded NF Client from NF page, and also the latest patch. Tried a whole host of
things but its still not working.

Also every time after the above crash from login screen, the updater again and every time
downloads 8k of files and when NF is loaded after the update, the
(http://i55.tinypic.com/t66tk0.png ) error comes up.

We would be grateful for any help.

The error shows up on the login screen, when it's checking those 5 points
and 'Interface.spr' is the 2nd point
It looks like this
http://i55.tinypic.com/t66tk0.png

Could you get us the actual error code? Does it happen with the file check after the game
loads up of prior as in right after the patcher goes away?

propably
interface.spr

I have same problem and my computer is better than his :P

Does it say what file?