Unable to launch D:/Everquest2/EverQuest2.exe - 740: The requested operation requires elevation. Prior to experiencing this error, whenever i hit the play button I would get a black screen and the game would crash.
This specific error is usually because the way your computer is set up (the UAC, specifically), you need to right click the icon and select "Run as Administrator".. I would try that first.
I put my game under c:\users\public since that defaults to giving the owner of the file full access. You could also go into the settings for the folders/files you have on D: and change them to allow full control rights for authenticated users. (Right click on folder/file, click on properties and then on the security tab and edit) Be sure you only do this for the game folder on down and not the whole disk drive.