|I don't think the above information is necessary. External hard drive use is pretty straight forward. |
Does the external drive use USB to connect to the computer?
Does the external also use AC power?
All you should need to do is connect it and Windows 7 should find it.
If you want to clean it up you can format it or go one step further and delete all partitions and create a new partition and then format that partition using NTFS.
To work with the drive you can go to Windows Disk Management to view the drive even if it is not formatted. If it is formatted then you should see it in Computer.
To get to Disk Management: Go to Start> Control Panel> Administrative tools> Computer Management> Storage> Disk Management. Right click on the External drive to see a drop down menu of choices to perform.
One important note is to be sure to always use the "safely remove" icon that will show in the tray by the clock once an external is connected. This is so the partition does not get corrupted.
If you are still not sure, feel free to ask more questions.