What causes this?

[LesStrat]

This occurred with my previous PC. For the last few months this has occasionally happened with my current system. The screen becomes blurry.

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There are hazy, vertical lines that shimmer on the screen at times, too. I might go back tomorrow and the screen will be clear. What gives?

[Big Flannel]

Loose vga connection?

[lreese]

Old age?

[Dr. Vegetable]

Alcohol and pills?

[lreese]

I've seen something like that on an old CRT.

I'm assuming that is a LCD/LED of some sort.

[GoldenVulture]

This occurred with my previous PC. For the last few months this has occasionally happened with my current system. The screen becomes blurry.

---

There are hazy, vertical lines that shimmer on the screen at times, too. I might go back tomorrow and the screen will be clear. What gives?

Same monitor or a different one ? Can you put up a shot of good operation ?

[LesStrat]

Maybe when it clears up again.

[GoldenVulture]

Same monitor or a different one ?

[Dr. Vegetable]

Newer monitors communicate with the computer to tell it what their native resolution is. As others have suggested, it could be a bad monitor cable causing the system to decide that it has a vanilla VGA monitor attached instead of your fancy hi-res LCD panel. The system sends out a low-res image and your monitor dutifully scales it up to fill your full screen.

Check your Display Settings to see if it is auto-detecting your monitor type correctly. You may be able to force the resolution in there to match your monitor.

What kind of monitor are you using? What kind of connection? (i.e.: VGA, HDMI, DisplayPort, ...?) Is the cable molded into the monitor, or can you maybe replace it with another one?

Have you tried spraying Cheez Wiz into the vents on the back of the monitor?

[GoldenVulture]

+1to all of the above except for the cheese whiz, spray on cooking oil is far better.

Also installing drivers specifically for the particular monitor you have, may help. These are available usually on the internit from the monitors maker. Alternately they can be found on discs if they are supplied with the monitor.