Windows 7: It detects a nonexistent second monitor - the cursor goes out of view

Please take into consideration that I'm translating terms from my language, so the actual Windows 7 options names can be different.

Post edited for recapitulation of the problem.
Sometimes my cursor goes out of view (to the right). I know that the cursor is almost invisible when it hits the right, but it's not that, it's actually going far off the screen and I have to move the mouse a lot back before seeing the cursor again.
This happens because windows detects a second nonexistent monitor.
If I go to "Screen resolution" and I click "Detect", another monitor appears on the right, near the first one; and it says: "another display not detected".
Clicking on it it says:
Screen: disponible output screen for: ATI Radeon HD 5700 Series.

When I first log in, the mouse stops where it's supposed to stop. I discovered that the "bug" happens when I logoff and log in with another user. When logging off and returning to my account, if I move the mouse at the right edge, it goes off the screen, on the ghost monitor to the right.
So I have to go to screen resolution, clicking "Detect" and "OK" and then everything gets ok.

This problem is annoying because sometimes you just happen to lose your pointer.
Also, closing a fully maximized window with the "X" is annoying because the cursor goes too far and don't hit the "X" button. You have to slowly point at it, you can't do fast moves.

On the Monitors category of Device Manager there's only one monitor:
generic monitor plug and play. ID hardware PHLC074, which seems correct since its Philips.
I'm using VGA (connected on the VGA input of my ASUS EAH5770 CUcore).

I played on the "Screen resolution" window a lot, but whatever thing I do the problem re-appears the next time I load the OS and I log in with multiple accounts.
My monitor is 246EL2SBH Philips, my GPU the ASUS EAH5770 CUcore and my motherboard it's PC-AM3RS890G (Sapphire).
Monitor's and GPU's latest drivers are installed.

What I tried
Formatting Windows. So it's not about old monitors/old GPUs.
Using "Screen resolution" to disable the ghost monitor.
Using AMD Catalyst control center to disable the ghost monitor.



dsperber seems to have that problem too. Please see its post so you can also see an image with the problem (he has two monitors and the third nonexistent one appears on the right; I have one monitor and the ghost as the second one): It detects a nonexistent second monitor - the cursor goes out of view

Is this a bug of Windows 7?

Are you saying that Catalyst Control Center thinks you have two monitors connected but you only have one? Strange.

Incidentally, I too have a Sapphire dual-DVI HD5770 in my machine (ASUS P5Q3). But I actually DO have two monitors... both Eizo 24" LCD's running at 1920x1200 each.

Anyway, you can certainly get rid of the extended desktop, i.e. the phantom second monitor using CCC.

Right-click on desktop, select Catalyst Control Center. Then go into Desktop Management, Creating and Arranging Desktops.

If you really do see "1" and "2" then for some reason the HD5770 thinks you have two monitors connected! Very odd.

But you can certainly disable "2". Just right-click on the second monitor icon in the lower part of the display, and select "disable".




Does that help?

Actually: right click on desktop ->screen resolution, but yes, I didn't think about changing that on CCC. It seems it works now. Thank you.

Damn, problem still not solved. The problem appears again. Now the second one is "generic non-plug and play monitor", 1024x768.

Did you ever actually have two monitors plugged in at one time?

No, but I had a different monitor some months ago, which then I've thrown away.
I've recently restored the Windows partition from an old backup (this is how I re-install windows), but maybe this backup still has some settings of the old monitor, so this could be the cause. Even if this is the case, how could I solve this (apart re-installing windows of course).

Have you tried plugging the monitor in to the other port on the graphics card?

Cannot. The other input is DVI and I don't have such cable. Do you think that the cause could be the VGA connection? Weird.

The actual cause is the old image still has the old monitor in it, look in device manager and see if there are 2 monitors listed, pick the old monitor and delete it from there, restart and see if it recognizes your new monitor.

You can buy a DVI-to-VGA adapter, and then try that.

I believe that as was suggested that your previous situation has left indications in Windows that you actually have (or had) two monitors. And I fear that even if you switch your single-monitor situation over to the other port (with a DVI-to-VGA adapter) Windows will simply swap what it considers monitor #1 in a 2-monitor situation. I'm not sure you're going to be able to fix this "phantom second monitor" symptom at this point.

I had a similar situation just this week, as I'm still recovering from my own upgrade to an HD5770 (dual-DVI) card from an HD4850 (DVI and VGA). I actually swapped two machines, keeping the CPU and motherboard in each machine and reversing the internal peripheral cards and non-C hard drives. The HD4850 remained in the machine that had originally been a dual-monitor Windows 7, but with the machine reversal it now was in a one-monitor Windows 7 configuration. And the other one-monitor machine that got swapped... it had its HD4670 (supporting a single VGA monitor) removed and replaced by the dual-DVI HD5770 for my two LCD monitors, and was no longer a one-monitor Windows 7 setup but rather was now a dual-monitor Windows 7.

Well the problem was that I'd forgotten to "move all of the windows over from monitor #2 to monitor #1" on the HD4850 machine before I swapped it into its one-monitor configuration. Well now, even though Windows definitely knew I only had one physical monitor connected and for example automatically moved the taskbar over from monitor #2 to monitor #1, any time I would open a program or dialog window (e.g. OPEN or SAVE AS...) which had previously opened on monitor #2, well it was now "off-screen" in the one-monitor setup. And there is no way to get it back onto monitor #1 with keyboard shortcuts, that I know of.

I ended up having to take this now one-monitor HD4850 machine back upstairs and temporarily re-connect it to the two monitors up there, and reconfigure the HD4850 to once again temporarily be dual-monitor. I then had to open every single program to see where that window went, and if it was on monitor #2 I dragged it over to monitor #1. Same with all OPEN and SAVE AS dialogs, Notepad, Firefox, Office programs, etc., etc..

Only once all windows had been brought over to monitor #1 could I now use CCC to disable monitor #2, disconnect the machine, bring it downstairs and reconnect it back to the one-monitor setup, and now everything opened just fine.

Again... the problem is because of the residual information all over the place regarding your former setup. If you don't mind reinstalling Windows from scratch with the new hardware setup (including new video card), you will now no longer have any problems. But replacing a video card (or going from a dual-monitor setup down to a one-monitor setup) is not easy or painless.