You can add a second display to a PC by fitting a graphics card to a PCI Express x1 slot: just don't expect great performance. Our Helproom Editor explains.

QUESTION I'd like to add a second display to my PC, which has only one monitor output. I've looked inside and the only expansion slot available is a single PCI Express x1 slot. Can I use this small slot for a graphics card? Mark Emery

HELPROOM ANSWER Contrary to popular belief, you can use the spare PCI Express x1 slot for a graphics card, although you shouldn't expect a level of performance suitable for gaming. However, for general 2D application use, it should work just fine.

The best choice for you will depend partly on what graphics processor is currently installed. We would suggest sticking with the same GPU manufacturer if possible, since this can avoid you having to install multiple graphics drivers that can conflict with each other.

So, if you have an AMD CPU with integrated graphics, go for an AMD Radeon HD graphics card; if you have nVidia graphics built-in, then go for an nVidia GeForce graphics card.

It may be preferable to disable your integrated graphics and use two outputs from a dedicated graphics card to drive the separate monitors. In this way you can avoid having two graphics drivers installed. An example of an nVidia card would be a GeForce 210, such as this one from Club3D.

The same company also makes a PCI Express x1 edition of the Radeon HD 4350, get it here. Most PCI Express x1 slots won't physically allow you to insert the larger connector of a x4, x8 or x16 card, but some are built with open-ended sockets that do. In these cases, it may be possible to use a standard PCI Express x16 card in your x1 slot. It won't offer the usual level of physical stability provided by the locking mechanism of a full-length socket, however.

If you don't have room even for a PCI Express x1 card, or would prefer not to have to open up your PC case, you can try a USB graphics card. These provide a VGA or DVI output. This will provide reduced performance and image quality, but greater flexibility and an easier installation. See also: Group test: what's the best graphics card?

See all How to articles. Get free tech support in the Helproom Forum.

Visit Windows 7 Advisor for more Windows advice.