Test this out on just one of the troublesome files first. If it works for one, try it on more of the files.

First check to see if it's simply that the file is tagged as some kind of a web download and so it's considered to have come from an unsafe location:
- Right click on the file and select PROPERTIES.
- At the bottom of the properties box look for the text "Security: This file came from another computer and might be blocked to help protect this computer."
- If so, there should be an UNBLOCK button next to it. Hit that.

If that isn't the issue, then try this.

Try editing the security policies of the file, see if you can Take Ownership and set it to access "everyone" to be "full control".

If those don't work, let us know and we can try other stuff.