My computer wont run Coh updater?

I am trying to download City of Heroes...or at least open it on my cousions computer so I can play on my account. I clicked on City of Heroes icon and it said that I must use Coh updater first. Now this little pop up thing comes up saying : Rename failed to delet target XXXXXXXXXXXXX this file may be in use by another program....blah blah blah.... Then it says if all else fails restart your machine. I did that but now it wont work. What should I do? I'm good with computers os just give me directions please.