You have a branded computer, it is a Fujitsu desktop. The fully compatible drivers are provided with your system manufacturer.
I suggest you to verify if you already have the latest BIOS version, latest Chipset driver. It is a very good idea to run “DeskUpdate:Automatic driver update” utility.
Before running Fujitsu DeskUpdate application, uninstall and delete the current graphics driver.
thanks a lot for answering. i applied before all the suggested steps but the problem continuous. i think that the problem could be on the new dell monitor.
Thank you for your feedback. Let me know if you need further assistance.