If you are positive that you did everything correctly; do the following.
First, remove your usb from your computer then go to the Control Panel on your PC and click on Classic View.
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This should show up, then click on Folder Options.
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This should show up. Click on the view tab then check and unckeck the boxes just like what you see in the following image. Click Apply then Ok
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Now, plug your usb back into your PC and look for the eid_root_key.
You can change back your folder options after that.