Go to Options on the Tools menu and then select Documents in the Environment node. (If Documents does not appear in the list, select Show all settings in the Options dialog box.)
Put a tick on "Miscellaneous files in Solution Explorer" and Click OK.
(This option displays the "Miscellaneous Files" node in Solution Explorer. Miscellaneous files are files that are not associated with a project or solution but can appear in Solution Explorer for your convenience if you tick this option.)
Locate your file in the Solution Explorer under "Miscellaneous Files". Then drag and drop your file to where it should belong and voila! This will copy the file to where you drop it. You may now safely delete the older file under Miscellaneous Files folder if you wish to do so.