Hi, 

Can you confirm how you are connecting the monitor? For example, with an HDMI or DVI cable. If you look at the back of your X51 system, you will see the on-board HDMI port at the upper part of the system and the discrete video card ports at the lower part, confirm which port you are connecting your monitor to. 

Hi,

Thank you for confirming this. Have you ever received a blue screen or video driver crash message? Which Bios version are the systems running?

No, I haven't received a blue screen or video driver crash message.

I don't know where can I find the Bios version. Last week I downloaded a new version of the Bios from Dell Support and the PC never wake up. Then I restart the PC from the factory configuration.

Attached a Print Screen of the Start. Look at the symbols at the corners of the screen. All of them are squares. This is the beginning of the fonts disaster.

Hi, 

Open MSCONFIG to check the Bios version, it usually shows in the middle of the window. You can open MSCONFIG from the search menu. 

I do get the "video driver quit working and has restarted", message, is there a fix to this.

Not to mention the sound of the fans and/or hard drive running at high speeds.

monitors hooked to dvi

win 10