HELP!!! Disk Copy Error

I finally got the demo downloaded (6th try). And, this time I am getting the error this file cant be opened because the application "disk copy" cannot be found.

I have no clue what this means. Any suggestions? The first time I tried to open it I got this same error and someone suggested I put the file into my hard drive and then try, and I did this and still am getting this error.

Please help!

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Get the newest version of Stuffit Expander at (url="http://"http://www.aladdinsys.com")http://www.aladdinsys.com(/url) . Then open it up using that.

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