As govpatel suggested, installing a fresh copy of WordPress may be the way to go.
I thought you might want to see these instructions for moving WordPress:
I'm not sure which situation applies to you (for example: moving to a completely different server, moving within the same server, etc.). Make sure you review the instructions that apply to your situation. Keep in mind too that your files you originally copied could be corrupted. It might be worth starting over with a fresh download of the original site files.
You could also try a fresh install on your new domain/subdomain. If you're able to do a fresh install, you could then follow the instructions for Moving WordPress to a New Server with Fantastico from the Moving WordPress instructions above. The steps for moving over your old files to your new install would be the same.
Here are the instructions for installing WordPress, either manually or through several popular account management tools:
Let us know how this goes for you.