I can't take a screenshot.

[Nappoleon]

I can't take a screenshot.

Simply no buttons work.

I changed the shortcut, the folder and nothing worked.

[Jaunitta 🌸]

Have you checked Steam>settings>Ingame, and the Use Overlay is ticked.
F12 is the default key.

Some programs like the GF Experience also uses the overlay disable the GF Experience overlay if you use it.

[Zekiran]

Also make sure that they're not being taken by going to the actual steam / userdata / yournumber / 760 / remote / game ID number <=== folders where screenshots are stored. Find the game's id number, and look there for screenshots and a thumbnail folder. if there is nothing there, something's wrong. if there IS something there, make sure that you have enabled the popup window to notify you of them after the games close.

That is, for some stupid reason, found under STEAM > SETTINGS > CLOUD - make sure that the right box is checked. Restart Steam after you do things, to see if they stick, too.

[SomeGuy712x]

Also, make sure the game you're playing doesn't reserve F12 for something else. For instance, an RPG Maker game like Helen's Mysterious Castle has F12 as the reset game button, and thus F12 won't work for screenshots, so you'd need to change the Steam screenshot key to something else.

[AK-47_OP]

lvlxd

[Cathulhu]

Make sure the Steam overlay is enabled and working in the game, as that is required.

[boogie268]

It is probablely your key board in flight sim 2004 v was pressed in order to take a screen shot. f12 normally in FSX i have had problems in flight time. Boogie.

[Nappoleon]

Thank you all for your help.

I found that Radeon Live was somehow causing the problem.

I reinstalled Radeon drive and solved the problem.