Changing option/alt key shortcut

[GordonLol]

Hi everyone,
Whenever I press the option/alt key it brings up the 'show all windows open' screen; I have a feeling I set this shortcut when I first got my macbook. I need to change it now as I need the option/alt in photoshop, where showing all open windows is not very helpful! I've looked for ages in the keyboard settings and googled to no avail.
Thanks for the help and hopefully I'm in the right place!

 

[dyt1983]

edit: To remove personally identifying information not relevant to the thread.

 

[GordonLol]

Thanks for the reply. I've spammed reset to default on all the options prior to posting here! It's really driving me nuts

 

[dyt1983]

edit: To remove personally identifying information not relevant to the thread.

 

[DeltaMac]

Your Mission Control pref in System Preferences, should show the set shortcut key for Application Windows, and should show your Option key as the selected shortcut. You could change that shortcut to something (anything) else

Or, unless you have a LOT of different custom shortcuts, you could set those to original defaults by going to your user/Library/Preferences folder, and then trash the file "com.apple.symbolichotkeys.plist"
Drag that file to the trash, then (important) either log out of your user, then log back in, or simply restart your Mac. A new file will be created for those settings - all set at original defaults, and then you can change those shortcuts to what you like!

 

[GordonLol]

It says application windows shortcut is ^+down arrow
I'll try deleting the settings thanks!

EDIT: cannot find the file to delete in the folder you've specified arghh