Two ways exist that don't require downloading anything, otherwise there are several methods.
The first is to open up the Computer link on the desktop, right click on the secondary drive, select format, and I trust you can take it from there.
Another option is to use the disk management tool. It's a bit buried being is that it's in Control Panel>Administrative Tools>Computer Management That will let you partition the drive as well as format it.
I suppose you could also use the format command from the command prompt if you felt so inclined.
I have a laptop with 2 HDD, I need to know how to format the secondary HDD?