I am using OpenSuse 13.1 with KDE.

When I start an application the window is not visible on the display. It disappears to the left of my desktop.
When having a pager in the taskbar (2 desktops) it can be pulled back inside the display but when having only one desktop (no pager) it is difficult to find where the window is.

Is there a way to make sure a window is always opened on the visible part of the display?
Or is there a way to resize the desktop to the size of the display?

Thanks in advance.

I'll try and help by making a guess. Can it be that you have a desktop size that is bigger than what is displayed on the screen?
Like having a desktop size of 1600x1200 but display only showing 1024x768 pixels.

It can be so that moving around the mouse pointer at the edges of the screen "moves focus" so you can see different parts of the screen.

But it can also be that what is actually shown on the screen is an absolute part of the total display, and that you cannot reach some of the desktop area.
This can happen on laptops where one installs the OS with a big resolution external monitor, and thenafter uses the laptop with only the internal LCD that has less resolution.
It can also happen when installing with two monitors attached, and thenafter only working with one of the monitors attached.

These things can be setup properly in the system settings dialog for display, so the laptop monitor switch works properly so one can select between external monitor at its best resolution, or the internal LCD at its best resolution, or an extended desktop (xinerama) using both screens as one desktop.

So, my guess is that the display resolution is not set the same as the actual monitor resolution used?

You are right wroom.
xdpyinfo shows:
dimensions: 3360x1050 pixels (886x276 millimeters)

I have tried to modify the size to 1680x1050 using randr.
But I have messed up my configuration doing so.
Do you know how I can change the size of my desktop?

SOLVED!
The command
xrandr -q
showed
Screen 0: minimum 320 x 200, current 3360 x 1050, maximum 8192 x 8192
DVI-I-1 connected primary 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
1680x1050 59.9*+
1280x1024 75.0 60.0
1280x960 60.0
1152x864 75.0
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
640x480 75.0 72.8 66.7 60.0
720x400 70.1
VGA-1 connected 1680x1050+1680+0 (normal left inverted right x axis y axis) 474mm x 296mm
1680x1050 59.9*+
1280x1024 75.0 60.0
1280x960 60.0
1152x864 75.0
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2

I then used
xrandr -s 0
and it showed
Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 8192 x 8192

I am quite happy now.
Thanks wroom for pointing me in the right direction.

Ack! Just finished the below text when i see your issues are already solved. Good!
But i still include the text to possibly help someone else.

---

3360 / 2 = 1680 pixels.

So you probably have a dual monitor setup. (Side by side).

Maybe most straight forward is to klick on the Program icon, then on SUSE, then on KDE System Settings.
Then you click on Display and monitor.

There exist many other ways to get to the display settings, but this is the direct approach.
Depending on OS version, selected desktop manager and others, the naming convention may differ. For example, my "start button" / "Program icon" is called "IceWM" on this computer.

When you are in the Display and monitor dialog, (or "Display" or whatever it is called on your computer, you will probably see settings for more than one monitor.
First you have to do is identify which monitor you are actually using. When you know which of the monitors you use, set the Primary output to that monitor. Also set its Position to Absolute 0 0. Then choose apply.
Next you check that it has the correct Size set. Should say something like 1680 x 1050 (Auto). If you had to change it, then choose apply.

Now for the other monitor. Set its Position to either of Absolute 0 0 or Clone of the first monitor. Then choose apply. This should limit the display size to what you see on your monitor.

When you are satisfied with the setup, choose Save as default. This will make the current setup default, and what comes up the next time you log in.

Please observe that for laptops the function key for switching between internal, external or both screens have an effect. If will determine which is the primary display, and which display may be a clone of, or used besides the primary display. On an EEEPC the funktion key sequence for switching screens is Fn + F8.

When everything is setup correctly on a laptop it is possible to swap between internal, external and both screens with the proper settings for each monitor.
The caveat is that if the external monitor is not attached during boot, it will most certainly get a lower "default" resolution of something like 800X600, which is quite irritating.

Issue is back again!
Had a kernel update today (openSuse 13.1 3.11.10-21-desktop) after which the issue occurred again.
And even worse!
Both my solution and yours cause an empty screen after re-login and the system hangs.
When I check after the modifications everything seems ok. 1650x1050.
Even CTRL-ALT-F1 or ALT-F1 to switch to a console doesn't work.
The only key combination that the system responds to is CTRL-ALT-DEL.

Whatif you connect a monitor to the other VGA port? Do you see your desktop on that monitor?

It can be that the video driver has an issue with which port is #1.

From the back of my head i recollect some dual VGA adapters have this issue.

Are you really sure the system hangs? If you ping it over the net, does it answer? Can you log in through ssh?

I have all files removed from /home/user and logged in with that user.
KDE does generate new files and I see a fresh (working) desktop.

Then I connected a second VGA monitor. The screen is blank. But when I logout on the first screen it switches to the VGA screen. When I logout there it stays on the second VGA screen.
After reboot I am back on the primary monitor (when the second one is disconnected).

No, the system does not hang. Just the desktop appears to hang if you do not have a second monitor.

I have a video card GeForce 8500 GT with video driver Nouveau 3.0 Mesa 9.2.3.

1) Have a look at the configuration in the /etc/X11/ directory.
Is there a xorg.conf file?
Are the files in the sub directory xorg.conf.d/ changed from the default installed state?
Are there any user local X config files in the "skeleton"/default user directory that gets propagated into new user home directory?

2) Have a look at the logs in directory /var/log/ . Especially the logfile(s) "Xorg.*.log".

3) Try installing the NVidia driver for the GeForce 8500 GT. Will the problem go away just by changing from the Nouveau driver?
From the back of my head i come to think of people having issues with the Nouveau driver, and the fact that it has never worked for me.
Therefore i always go for the NVidia driver.

When i work with video drivers, install/tune, i usually do that from an SSH session on another computer.
Make the changes, then use "rcxdm restart" to test.
And if that is not possible i change runlevel to work in the text console, and test the configs with startx instead of using XDM.

I could not find a xorg.conf file.
So, I downloaded the latest nvidia driver for my video card using the OpenSuse 1-click-install.
Rebooted in runlevel 3.
Ran nvidia-xconfig.
Tried startx which worked fine.
Rebooted in runlevel 5.
Problem solved (again ;-) ).
Only one monitor visible in System Settings and size is 1680x1050.
Thanks.

Good to hear.
Lets hope the problem stays solved this time.