Since the official website of the program does not exist anymore, you will need to do everything manually. First, install a product viewer application to retrieve the key of the installation, then copy the whole installation folder to the new operating system. To avoid compatibility problems, right click the executable file and go to Properties > Compatibility. Choose Windows XP from the list and launch it with administrative privileges. Input the serial number you previously saved, and it will work. However, this is an old product. Try to use something like Virtual DJ which is compatible with Windows 7, and it's getting updates regularly.