Windows 7: Detect new secondary monitor without rebooting

Had an 19" for my secondary monitor, now have a 23". Detect doesn't see it and the resolution I need is not available. Sheer laziness here (and have an ISO downloading at the moment), but is it possible to force a re-detect without rebooting?

EDIT:

Please, I'm not looking for a "how do I setup a secondary display?" kind of answer here.

Thought I was pretty clear, but the issue is that if you swap in a different secondary monitor (and this likely would be the same if you had only one monitor; I suspect it's a limitation of the video card as commented below), it's not obvious whether you can "trick" or coax Windows into detecting the newly-swapped in monitor; I know when you reboot, Windows detects the new display, just wanted to know if this was possible without rebooting.

gravyface

Posted 2013-01-31T16:55:32.027

Reputation: 1 144

Is there a utility available with your video card? Sometimes those are handy for customizing the display options from the tray. – Austin Sanderson – 2015-08-29T00:01:37.780

Maybe I'm not understanding the problem... I connect and disconnect from a half-dozen different monitors using VGA and HDMI, at least 20 each week, and run a single display half the time on my current and previous Windows 7 laptop and never reboot or shutdown/startup during the week, in and out sleep all the time... Windows just handles this seamlessly. I don't think there is anything your supposed to do as long as the monitor is PnP compliant, which anything in the last 10 years. What am I missing? – acejavelin – 2016-04-20T00:16:19.213

Answers

I have been able to do this, but it is an expert trick. From the comments it sounds like you might be comfortable with this. I am assuming you are familiar with the tools I am describing. If you are not familiar with the tools being described, I do not recommend this trick.

It involves disabling and re-enabling the device driver. The trick works on Windows 7; I have found it does not seem to work on older (e.g. Windows XP) versions; those older versions require you to reboot, which is what you are trying to avoid.

I know of two ways to accomplish disabling and re-enabling the device driver:

Device Manager
DEVCON

With Device Manager, right click on your display adapter and disable. The display will go into VGA mode. Then enable. The display adapter should re-initialize and find the second monitor (assuming it is powered on).

Using DEVCON you will need to find the PCI address of your adapter first. Then you can use commands like the following in a batch file:

devcon disable "PCI\VEN_1002&DEV_95CF&SUBSYS_21431002&REV_00"
devcon enable "PCI\VEN_1002&DEV_95CF&SUBSYS_21431002&REV_00"

trindflo

Posted 2013-01-31T16:55:32.027

Reputation: 152

This should be an accepted answer. It works perfectly for the question asked. It works for Windows 10, too, with the Device Manager approach at least. – alficles – 2017-03-02T03:15:34.507

The Device Manager one worked for me using Win 7. – raphael75 – 2018-07-15T23:21:53.223

If this solved your problem, you should consider updating that driver to the latest version. I did this, and it fixed my problem permanently. – P5Coder – 2019-09-18T05:25:29.623

-2

Yes. Right-click on the desktop, select Display, select second screen (should be grayed out) and select "Use this display." You can then set it to Mirror, Extend, Primary, etc based on your needs.

Screen should look similar to this: enter image description here

Kruug

Posted 2013-01-31T16:55:32.027

Reputation: 5 078

1I know how to setup a second display; I had a 19" in there. When I plug in the new 23", it doesn't see it. – gravyface – 2013-01-31T17:06:40.383

1If the 2nd display is on the vga then it probably only does device detection on boot. Depends on your graphics card/chipset as much as software settings. – James Snell – 2013-01-31T17:20:10.183

1It's on DVI. I'll take a look at vid card settings. – gravyface – 2013-01-31T17:22:02.567

@gravyface Is this a second monitor, or an extra monitor into an existing dual-monitor setup (remember, laptop screens count)? Many times, you can only run 2 screens off of a single video card (yes, you can sometimes get more). – Kruug – 2013-01-31T19:40:10.233

2@Kruug et al: Please read carefully. There's two monitors (I said "secondary", root word "second" as in "monitor #2"). clearly you don't have an answer; not sure why you're still flogging your "dual display 101" answer. Can't believe this was upvoted either. – gravyface – 2013-01-31T20:42:44.843

@gravyface I am flogging my "Dual Display 101" because I don't know of our technical proficiency. Where I work, people would say second monitor and want 2 external screens and their laptop screen. To them, that's a second monitor since the laptop screen is their laptop. – Kruug – 2013-01-31T20:50:17.783

2My very first comment was "I know how to setup a second display"... it really doesn't get any more clear than that. Where I work, when people say I want a second monitor... it might just mean that they want a.. wait for it... second monitor. – gravyface – 2013-01-31T20:52:34.903

@gravyface I'd rather make sure I understand the situation 100% by going over redundant steps than not know the full situation and give you bad/wrong advice. Remember, you asked us...we don't owe you an answer. http://www.freenode-windows.org/channel-guidelines/help-guidelines

– Kruug – 2013-01-31T21:01:53.267