How to hook up a second monitor to a PC?

The Dell Studio 540 does not natively support dual monitors. The onboard video (integrated graphics) only supports displaying video to one monitor at a time through the ports that are included.

In order to get dual monitor support, you would need to buy an additional graphics card that supports dual monitor output.

Not at all knowledgeable about this. Can you advise on what type of graphics card do I need and where might I purchase it?

Just adding to TechieMD's accurate post.

The onboard video is disabled when the add-on video card was installed (probably by Dell).

Is there only one output on the video card?

Dual (or triple) video cards are usually not very expensive ($50 or so) if you are not going for high performance (such as gaming).

What ports do your monitors have?  A multi-output display card may have only one analog (VGA) output with the other output(s) being digital (DVI, HDMI, or DisplayPort).

This will get you three outputs for $30:
https://www.amazon.com/EVGA-GeForce-Passive-Graphics-01G-P3-1313-KR/dp/B004KABG1I/ref=sr_1_1?s=pc&ie=UTF8&qid=1472667597&sr=1-1&keywords=pci+express+video+card

The DVI is DVI-I which means that with an inexpensive adapter you can use it with VGA.  If both of your monitors only have VGA inputs, this would be useful.

There are many others that would do the job; this is just one example.

In answer to CompProbSolv, both monitors have VGA inputs (female). I have a VGA cable which connects the VGA input from the second monitor to the PC (there are two VGA ports ... but the second VGA port, which had a cover over it ... when connected  seems inert - does not work

What should I be looking for to answer your query about : 'is there only one output on the video card?'
No problem in opening the box. Not sure which is the video card.

I don't need the second screen for gaming etc. I want to use it when working on documents (in a situation where I want to have two documents on screen at the same time.  At present on my one screen PC I have to half the size of documents to get both up together and this is not satisfactory)

By the way I notice at back of the PC near the blue VGA socket there is another slightly longer whitish  socket (looks like 24 pins together, 3 rows of eight)

I have checked. It is a DV1-1.  I will get this adapter. Will get back to you when it is all done and dusted.

Thanks Nobus. Am awaiting cable. Will get back as soon as it arrives.

It arrived and is working perfectly. Thanks.

tx for feedback