Hi IshankJha
I am Dave, I will help you with this.
AutoPlay.exe was a file used to automatically open content on a CD/DVD or USB flash drive, and that was a major cause of Trojans being moved from PC to PC and so that file is blocked by default.
AutoPlay.exe usually references another file on the disk, and usually that can be started separately to perform the task.
Where are you trying to open an Autoplay.exe, is that for a specific software installation, or just in general on your PC, please provide gull details.
I was trying to open for a specific software installation.