I've tried to download the Photoshop CS6 Extended trial, but it was missing from the download assistant, so I just downloaded the version that was available, the 3D feature was missing, which is one of the only reasons I decided to get the trail for Extended, it's not grayed out, it's just simply not there.
My PC's specs are:
Windows 8 Professional 64bit,
CPU is an AMD FX-4100 Quad Core,
8GB of DDR3 RAM,
My GPU is a NVIDIA GeForce GTX 550ti,
What am I doing wrong?
There is only one install. It install extended. When you purchase a standard licence and activate Photoshop with the licence number the extended features are not available. There will be no 3D or analysis menus.
Like JJ said all the PS trials are Extended and 3D is available. If the option is grayed out it means your video card or driver is not supported. THe first thing to try is to go to nVidia's website and download the lates driver for your card and OS.
Then in Edit/preferences/performance check "use graphics processor". May have to look in Advanced Setting and change to Basic if you have problems with advanced.
The option can't be grayed out, because there is no option, also I know where it's suppose to be, it's not there, I haven't purchased a full copy yet so it can't be that either, I know my GPU is supported and the drivers are all updated, they get updated as soon as the update is released, the "Use graphics processor" option was already ticked.
Sometimes even the purchased version does not start with extended for some reason. An uninstall and reinstall seem to fix the problem.
But before doing that try resetting the preferences. Start PS and immediately hold down the Ctrl Alt Shift keys. If fast enough you will get a reset window. If you see splash screen you are too late.