Security app you all use and is it in a browser window?

Mine does it too sometimes, goes black like it loses signal and then comes right back on, mostly in XP and on my home PC.  Probably something to do with my nVidia video card drivers (even though they are always kept current).  Although somewhat inconvenient at times, I don't worry about it.

Wild guess: Are all the effected PC's on the same UPS, surge protector or AC supply line/breaker?

 If so, have an electrician check your  buildings electrical system out or at least the supply to the rigs in question.

Wild guess number two:  Do you or the others have unshielded speakers near the monitors?

Flash how?

If like Lightstar described, that has usually meant very bad things in terms of the video card in my experience.

@Lightstar: You might want to check your video card and see if it's overheating.

Nope, not overheating Kitkun, both cards running at around 99 degrees Fahrenheit (38 degrees Celsius) or less at times.  Even when my son plays an intensive game the primary video card only goes up to 112 degrees Fahrenheit.

Cool new avatar Wiz

yrag: Not in browser. The PC screen just flashes as if the video drivers were going crazy. I guess the best way to describe it is it looks like someone taking a picture of my screen from the inside.

Lightstar: minde doesn't go black, it just flickers, flashes.

Wizard: not sure about a UPS, I don't have one on my PC as it's connected to the plugs built in to my cubicle where there are 6 PCs connected but doesn't mean there isn't one for my row. It's possible, however I have seen individual UPS's in some cubicles around me. No speakers on my desktop, only headphones and the speaker built into the PC case. It's a Dell PC with XP.

Kitkun: Flash, like a picture flash. Or flicker.

Uvah: I guess it is a cool avatar, can't see the whole thing though thanks to JU's style of showing enlarged versions in the comments where you can only see a piece of it.

Your building's power supply.

I said the same thing but used one more  r and one less ' .

It could be lots of things, including EMF, stray RF, line noise, even a microwave heating up a pizza nearby. 

CharlesCS, are all the affected PC's in your cubicle group?

I agree....

In a browser window, Flash can cause it and some Security add-ons flash on an app initiation. A 'bunch' doing it isn't anything inherent to any software/ hardware issue as it relates to the machines.

I would have someone check it out..... you, in all likelihood, have an overload somewhere caused by something turning on periodically. Computers don't do well under those circumstances.

....... it certainly isn't Big Brother.

OMG that hurt........................

Until now, I've never felt a need to copy, print and frame a forum reply.

I edited it......all better now???

......... try it..... even at your age, it'll make you feel warm and fuzzy.

I'm not sure what you edited. I was referring to the fact that you and Jafo agreed on something.

 As for feeling warm and fuzzy, we have threee cats for that, all warm and all fuzzy.

I edited it to separate quotes so you old fuckers wouldn't get confused..... 

yeah....that's the part that made my dick hurt........

BTW Dumbass: We saw your reference in  # 3. Unfortunately, both Jafo and I are incapable of reading anything misspelled........