1. Visit the video card manufacturer's website and download, then install the latest driver for that card.. (If it's the same default card as came with the computer, then the correct driver may reside at the Dell website.
2. Change the screen resolution to something other than you currently have it.. (RIGHT click on the desktop, choose "Personalize", then select "Display Settings", then move the resolution slider to a different number. If you wish to increase the resolution above the default; and you must remember that your monitor must support this new resolution, then click the Advanced Settings button, then click the Monitor tab. In the monitor tab window remove the tick mark from the 'hide modes that this monitor cannot display', then click Apply followed by OK. An extended display resolution range should now be available.) Depending on the size of the monitor, which you didn't give us, you may need to change it to the default "native resolution" for things to look good. Give us a little more information and we might be able to tell you the native resolution for the monitor you're using.
3. If you've already done the above steps, then occasionally the constant changing of the display settins is caused by a faulty codec that may have been installed. Try removing any unusually codecs that you may have installed for your system.
In addition, if your system has the option for dual monitors in your Display settings, make sure you have the monitor set as "primary".
And finally, and this seems to work for most, click on Start, then type "Run" in the search box, then press the "Enter" key. Now type "msconfig" (without the quotes), in the Run line and click on OK. When the System Configuration Utility opens, in the "Boot" tab, UNCHECK the box next to "Base Video", then click on "Apply", then OK and restart the computer.
Hope this helps.
I had a new video card installed by a Dell technician. The desktop image and fonts are distorted horizontally now - very annoying.
Have tried on the Control Panel under Personalization, Display Settings, to follow the suggestions listed there. After every re-boot the problem is still there or even worse.
My PC is a Dell XPS 420 with Vista.