You have a new Seagate expansion external hard drive which you purchased so that you could install Windows 7. Now that you have Windows 7 installed you can't seem to get that device to become recognized so that you can restore your programs to your computer. You have gone into disk manager and it shows an unidentified unit without any properties or set up software.
According to an How to use an external drive without any special software page for that particular model, you don't need to install any software. You can just drag and drop files to and from your external hard drive. Windows 7 should detect that hard drive and install those drivers for it.
Please try to reinstall that driver for it. Click on your "Start" button then select "Control Panel". In control panel select "System and Security". Choose "Device Manager" from within system and security.
Look for your Seagate device under "Disk drives". Right click on it and choose "Uninstall". As long as your Windows 7 computer is connected to the Internet you will be able to reinstall that driver for it. There should be a small computer with magnifying glass icon called "Scan for new hardware".
Click on that icon and Windows should attempt to detect your external hard drive again. As long as Windows updates is enabled it should reinstall your driver for it. Also, you might want to reboot your computer after a driver installs.