You can buy a monitor switch box or a second video card to connect two SVGA monitors to one computer. You'll need Windows 98 or Mac OS 6.0.7 or newer.
OR
Configure Multiple Monitors and Dualview with Windows XP :
If you have a desktop computer and you want multiple monitors, your best bet is to buy an external monitor and a second video adapter that supports multiple monitors. Here's a list of Supported Display Adapters for Multiple Monitors and Dualview. Alternatively, you can upgrade your current video adapter with an adapter that can connect directly to multiple monitors. You can find such video adapters for less than $200 at most electronics stores—just make sure that it's compatible with your computer and has connectors that match the monitors you plan to use.
If you're a laptop user like me, you don't have the option of adding another video adapter, but your laptop might support using Dualview with an external monitor and the laptop's built-in display. If it does support Dualview, just do what I did: plug a monitor into the external VGA port of your laptop and turn on the Dualview feature of Windows XP. To turn on Dualview, follow these steps:
1.
Right-click the desktop, and then click Properties.
2.
In the DisplayProperties dialog box, click the Settings tab.
3.
Click the Display list and select your external monitor. If you do not see multiple monitors listed, your computer hardware may not support Dualview. You can still use MaxiVista to configure a second computer as an additional display, however.
4.
Select the Extend my Windows desktop onto this monitor option. Click Apply or OK.
Now I can have different windows open on my laptop's built-in display and the external monitor. I can move windows between the two displays and even stretch windows across both displays. For more information on how to move from one monitor to the other, see Expand Your Workspace with Multiple Monitors and Dualview.