With the PC switched 'Off', you connect the two monitors to the two DVI connections at the back of your PC. At this stage it doesn't matter which monitor to which connection.
Now switch 'On' and start Windows in the normal way.
One of the two monitors will now show the Windows Desktop screen in the normal way.
By the time you get to this stage Windows will have recognised you are using one new monitor and will have kicked you off with the latest up to date the Driver for that make and model of monitor. If you have some time and patience you could at this stage (or later if you want) let a program called
Driver Booster 3 (Free) go through your whole machine and download and install ALL of your machine's Drivers.
(Whilst on the subject of being 'up to date' with things, you could also use a Free program called
Secunia PSI (PSI=personal software inspector) to check your whole machine for the latest versions of ALL the software you are using too. Doing this will obviously take a few minutes so you could leave this till later too.)
Anyhow, moving on with installing the dual monitors...
Then you go into the Control Panel in Windows from a click on the the Start Button at the bottom LHS of the screen. You need to open the Display section. Click on Screen Resolution. Here you will see how you can simply 'enable' the 2nd monitor and move (drag their icons) Monitors 1 and 2 into their correct '1 positioned to the LHS' and '2 positioned to the RHS' positions. Have a play around. You can 'Save' what you do or ignore it so you can't really go wrong. Change 'Resolution', position, identity (1 or 2), etc.
You could also see what you fancy wanting to watch on YouTube about the subject of: 'setting up multiple monitors' and, say using a 'Dual VGA graphics card'. It's the latter which will most probablty provide you with the second DVI connection.
I actually have to go out now. (Dog Training). Check out, say Toms Hardware at:
http://www.tomshardware.co.uk/s/dual+monitors/