Helping people with computers... one answer at a time.

Most laptops include a VGA or DVI connection for an external monitor. Setting it up is relatively easy, if you know the tricks and have patience.

How do I hook up a monitor to my laptop? I can not get the monitor to work.

I see people struggle with this all the time. It's actually somewhat frustrating, since the answers are actually simple, just not obvious.

You need to know the magic keystroke.

And you need patience. Just a few seconds worth, but you absolutely need it.

Most laptops built today include an external monitor connection. Most are VGA, but some are starting to include DVI digital video connections instead.

Laptop VGA connector
The back of my Dell laptop, highlighting the VGA connector.

The 'trick', if you want to call it that, is that they are not enabled by default. You need to take action to send video out that port. Typically, and this varies from laptop to laptop, there is a keystroke that does exactly that.

The CRT/LCD selection key on my Dell
The CRT/LCD selection key on my Dell Laptop

Unfortunately, it's not a simple as turning it on or off.

First, realize that in order to enable the CRT/LCD keystroke you typically need to be holding down an additional key; on my Dell it's a blue "Fn" key. It operates very much like CTRL or SHIFT, in that you hold it down to enable the blue functions that are printed on the key tops. So in my case it's Fn + CRT/LCD to enable the external monitor.

Second, realize that it's not on/off. Pressing the key repeatedly cycles though a series of combinations. For example, each time you press that key, you may cycle through these combinations:

"... give the new combination at least 5 seconds to take before you decide it didn't work. Be patient."
  • LCD (laptop screen) only, the CRT (external screen) is off.

  • CRT only, the LCD is off.

  • LCD and CRT both on, and displaying the same thing on both screens.

  • LCD and CRT both on, but displaying different things - together they form a larger virtual desktop where the LCD might be displaying the right side, and the CRT the left.

When you type the keystroke, the configuration changes to the next one in the list; when you reach the last, it starts over at the beginning.

Your list of configurations or combinations may be different, or in a different order. There is no standard, and each laptop may be different.

Third, and this is perhaps most important because it's the source of much frustration, it can take up to 5 or even 10 seconds for each new setting to take. And 5-10 seconds is a long time when you're standing in front of people trying to ready your presentation. I continually see people get very frustrated when they try, wait one second and assume that because it didn't work instantly it didn't work at all, and keep trying thinking that nothing's working.

If you take nothing else from this article take this: after typing the keystroke to change your LCD/CRT configuration, give the new combination at least 5 seconds to take before you decide it didn't work. Be patient. There are several hardware related reasons for this; most typically the time it takes your CRT or projector to 'sync up' to the signal that it's suddenly receiving.

The last combination where both your laptop screen and your CRT are on and displaying two different portions of a single virtual desktop warrants a little more clarification.

The likelihood of the LCD and the CRT being the same resolution or "size" in pixels is very low. You can see this when you look at the display settings in Windows:

Dual Monitor Settings

You can see that while my laptop's LCD is 1440x900, the CRT/VGA output is set to 800x600. While you can often change the resolution of the VGA output, it's unlikely that you'll be able to match the native resolution of your LCD. The result is what you see - a virtual desktop that's not a perfect rectangle. That's something you simply need to be aware of as you move applications between the two for your display.

I'll admit that it can be a little frustrating at first to get the hang of how your laptop handles external monitors and how those external monitors react, but once you do you'll find that the external VGA output on your laptop might be one of its most important features. Just ask anyone who's made presentations in front of an audience.

Article C3570 - November 22, 2008 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

November 24, 2008 3:42 AM

this is something really useful!

i presume the reverse is not possible? i.e. watching for example DVD player's output on laptop's LCD, because laptops dont have a video input channel?

i guess this is why graphic cards cant be added / upgraded in laptops

November 25, 2008 8:25 AM

RE:hook up a monitor to my laptop

Thanks Leo. This is very useful (I have a Dell Inspiron). I didn't try to hook the second monitor yet.

My question is : Do I need to install the monitor driver first?

Thanks, Dan

- Leo
November 25, 2008 8:36 AM

No drivers are needed. Just hook it up and go.

Richard Deem
November 25, 2008 9:45 AM

This is all fine and good for Windows XP. However, Windows Vista has this annoying feature called "Presentation Settings." Sometimes it comes on when I hook up my external monitor and sometimes it doesn't. When it does turn on, it flashes on and off about 10 times over the course of a minute before you can actually see anything longer than about 5 seconds. It defaults to preventing your screen saver from going on (which is useful if you really are doing a presentation, but not otherwise). In addition, Vista has the annoying "feature" of randomly going into mirrored, single or multiple displays depending upon what it "decides" to do when the external display is attached. The magical button may or may not fix the problem, and usually doesn't once you close the lid (since that is a different setting altogether on your laptop). The problems are actually much more significant than the article would indicate, especially if you are using Vista.

November 26, 2008 10:07 AM

Thanks all for the input. I'll feedback here as soon as I have a chance to hook it up. Fortunately, I could keep away from Vista so far but I don't know how long I'll be able to escape it. This is off topic but let me ask you this in case my 7 year-old XP machine gives up on me : Which version of Vista should I get? I just use my PC for the usual stuff and to develop applications in Delphi (32 bit). Thanks for your time.


Doug Proctor
November 26, 2008 10:59 AM

To Dan:
I choose not to go with Vista when I purchased a PC in June 2008, but I had to build it and purchase XP software. This is - and should continue to be - an option, and it just isn't that hard to build one.

Michael Horowitz
November 26, 2008 1:19 PM

A new connection for an external monitor is starting to appear called a Display Port. This is an interesting article on the topic.

November 27, 2008 6:57 AM

To Richard Deem
Yep! When I close and reopen the lid, the monitor is resized to the laptop screen size. I have XP.

To Doug Proctor
Keeping XP on a new machine is an option but I guess I'll go for Vista since I develop free/sharewares apps. For the moment, I give them to my friend to test on his Vista box. Getting Vista would make me independent. He has the highest Vista version (I don't know the name) but given the trouble he is having with it, I'd appreciate comments on the best Vista version for my purpose (just an Internet, office and development machine.

To Michael Horowitz
Great link. Thanks!

Lastly, how about connecting an external keyboard to a Dell Inspiron? I have 2 spare keyboards but couldn't find a suitable connector on the laptop.


November 29, 2008 8:13 PM

Vista should also be aware that Presentation Settings behavior may be masking another problem. The graphics card probably has software that controls some of the same things that PS does. In my case, updating the driver for my NVIDIA graphics card and then using the NVIDIA Control Panel (accessed by right-clicking on a blank part of the desktop) solved my problem. Now setting up an external monitor is easy and reliable.

November 29, 2008 10:28 PM

uhh i pluged in the cable into my toshiba laptop and put the cable into the samsung tv useing the vga cord.
it starts up fine but then it just cuts off... i don't use a dell so i don't know where the crt/lcd botton is it's just alot of pictrues which i don't know what they mean at the f1 f2 f3 ect. thing. i have found the fn botton though. the resilution is correct too.
if you could help me that would be great i really looked forward to playing on the big screen. anyways thank you if you could help me.I'm going to keep trying through trial and error but if you could get back to me thats great

How about checking with the documentation that came with your Toshiba, or the Toshiba support site. I'm sure it's one of those Fn+another key, but they'll have to tell you which one for your specific model.
- Leo

David Irwin
December 1, 2008 1:24 PM

They do make external video cards for laptops as well. They connect to USB and provide analog or digital video. I have an Aluratek model UAV 100F.

Ed Vance
December 6, 2008 4:11 PM

To: Jom

My AcerNote light laptop uses Fn key + F1 to show what F key to use with the Fn key.

jo mills
December 10, 2008 5:32 PM

I have read all yoiur advise, however here is my problem...I have a laptop OPS as windows vista. I hooked up the correct cable to my tv and plugged it into the port on my laptop. It acts like it wants to switch but says no signal. I am sure all I need to know is what "magic" key/keys to press to make the change. It worked once and I cannot remember what I did. I don't have a fn key CRT/LCD to press.How do I make the switch.
I am so frustrated.
Thank you Jo

dave macheca
January 10, 2009 3:19 PM

How can I use the laptop as a desktop? When I try to close the lid on my Dell laptop the monitor goes dark.?

April 7, 2009 6:09 PM

i have tried fn and the f8 combination sometimes it work an sometimes not

January 15, 2010 9:00 PM

hey iv got a vista and i cant connect my pc to my lcd tv Please help me thanks

February 22, 2010 4:44 PM

for my laptop i have to press Fn and F7

August 8, 2010 1:46 AM

Have broken Apple monitor. would like to link up new apple laptop monitor to old apple laptop in order to retrieve/transfer music and important files from old harddrive. Can this be done?

Paul Howard
August 22, 2010 10:31 AM

Have a Toshiba Satelite 1135-S1551. LCD monitor works fine until after it boots. I should see my desktop, etc but it's blank.

At first I suspected a bad video card but realized that probably isn't it because it works at boot up.

Any ideas?


September 26, 2010 11:53 AM

I have to press FN and f4, but i'm not seeing the pop up with the display settings, nor can i make both screens be different... Help please!

Check the documentation for your computer. From the article: "Your list of configurations or combinations may be different, or in a different order. There is no standard, and each laptop may be different."

October 9, 2010 6:32 PM

I have a Dell Latitude D510 Laptop.... shattered screen I am trying to put a monitor on it to retrieve my data on the laptop..... I press Fn and F8, I've tried everything nothing happens???? Any help out there????

LInda Flikweert
October 23, 2010 5:33 PM

Great help! the FN-F4 function worked right away. Thanks

Hai Pham
October 25, 2010 12:31 AM

Thank for that.
I have Lenovo T400 and Toshiba CRT 32" .
Is there any chance to make it happened?
Is there any others tip: I did change a lot in resolution and refresh rate :).
Thank Leo,

Danny Balanduk
December 29, 2010 7:02 AM

i can get my tv to connect to my laptop and it works great for about 10 seconds but then my tv goes black and stops getting a signal... when i unplug it and plug it back in it works again for another 10 seconds roughly but then disconnects again... how can i fix this???

January 2, 2011 11:34 AM

I have a dell inspiron 8600 and am trying to hook up a 2nd monitor. The only thing that shows up on the monitor is my wall paper. I can move my pointer arrow to the external monitor, but nothing else happens. any thoghts?

Not sure what you're expecting - it sounds like it's working. Open an application and use your mouse to drag that application window to the other monitor.

Alan Jiang
February 7, 2011 1:01 PM

I found the Fn and equivalent of the CRT/LCD on my Acer laptop, but the problem is, the screen of my laptop itself is not working, so when I push the button I have no idea whats happening (it's connected to an external monitor). Also, I can't log in or anything without seeing what I'm doing. Question-Will this method work before you're at the desktop (if you're still loading windows, for example)

Best I can offer is ... maybe. Perhaps probably? Prior to Windows 7 this was handled differently by each computer manufacturer. After Windows 7 it's often handled by the OS in response to the WindowsKey+P function.

March 22, 2011 9:59 AM

Many Thanks it was brilliant I am a Trainer and its going to help a lot.

Leona Torres
April 6, 2011 10:33 PM

i have a Polaroid flat screen and my toshiba laptop cannot connect to my tv can you help me please??? i cnt read my laptop very well my eye sight and i am in need please help

June 1, 2011 1:45 PM

I have a hp pavillion and the screen is damage. How can i connect the laptop to a desktop monitor?

alfred fonseca
July 19, 2011 10:37 AM

The above intructions are both in words and
graphics the best I ever saw, so why still cannot
connect my laptop to outside monitor? I am in
despair and don't know what else I can try.

July 19, 2011 11:11 AM

Thank you so much. I could not figure out why my other laptop was able to connect automatically and this one did not. Both of mines are Dells as well. Also, for the one that automatically connected I can close it and still have access to using the laptop-I too have a keyboard connected. Do you know how I can make it as where my other Dell does the same thing? As it bothers me to see 2 screens.

Mark J
July 19, 2011 2:36 PM

You might want to try the Display options from the Control Panel, and click on Connect to a Projector. That's sometimes worked for me.

August 24, 2011 7:11 PM

What do I do when my function key doesnt work because my kid spilled on it? HELP!!!

August 25, 2011 11:59 AM

Now I feel like a dummy! I'd been hitting F8 over and over, among other highly more sophisticated steps, only have the bright idea of actually LOOKING at the icons and noticed that on my HP Mini...It's F2, not 8. Sometimes I'm really blond.

November 22, 2011 3:06 AM

Alfred, try doing what Mark J worked for me, but only after the F8 thing.

Bill O'Dell
November 26, 2011 10:52 AM

I have a hp laptop and use a seperate monitor and keyboard. I would like to know if I can close the laptop somehow and still be able to use the computer?

Sure. Just make sure that the power settings are set to "do nothing" when the lid is closed. (Realize also that depending on your laptop this MIGHT interfere with airflow and cause it to run warmer.)

January 5, 2012 9:40 AM

i have a dell laptop and i just bought a new lcd tv and i can only get my computers background to show up on my tv. what do i do?

January 6, 2012 7:01 AM

Great Article. Thank you so much for sharing!!

February 5, 2012 12:37 PM

I tried to change the power settings to "do nothing" when the lid is closed but it has "sleep" as a default & I am unable to change it, even as the administrator. It says access is restricted. Any suggestions? Its a Samsung RV511 if that helps. Thanks-

Lucas C
July 12, 2012 6:10 PM

Is it necessarily bad to have your laptop hooked up to your monitor 24/7? I've heard of some cases of this resulting in the video card going bad.

I've certainly never heard of that being specifically a cause of a monitor going bad. It's just like leaving a monitor connected to any computer, laptop or not, as far as I'm concerned. Like anything it boils down to the monitor simply being "used" more, and perhaps that would lead to a shorter life?

September 8, 2012 10:41 PM

My Dell desktop screen wont light up after I have followed the directions above, is there anything i could be doing wrong?

January 13, 2013 10:37 AM

You my dear, are a genius!!!!!!!!!!!
Thank you :)

January 26, 2013 9:46 AM

Thank you so much! Really helpful

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