cp -r will get rid of the -i that's in there, or you can just take a look at your /etc/profile script, or .bash_profile, .profile, or .basrc you've got that has cp aliased to cp -i
cp -r can get nasty though, it follows symbolic links in stupid ways and can hang a machine if there's something still writing to a file say... there's an uber-cool option to cp now if this is a backup, try a simple:
cp -a
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