Under your main account, if you right-click AE and choose "Run As Administrator", does it work?
No, it doesn't.
Any other suggestion?
Permissions are messed up somewhere (in your preferences most likely).
One way to check would be to create a new, non-admin user on your machine and see if it launches AE. If it doesn't permissions are wrong on your user account.
Side note: This is usually a Mac issue; it's not common seeing it on Windows! So...congratulations?
Try going to C:\Users\YOURUSERNAME\AppData\Roaming\Adobe\After Effects\14.2 and setting the permissions for that 14.2 folder (and all containing folders) to be full access. If that doesn't do it, just try moving that folder to your desktop somewhere and launching AE without it present.
Let us know if that works.
I've created a new non-admin user and it launches!
The after effects folder has already full acces but one thing I've noted is that it doesn't contains a folder called 14.2 but instead it contains a folder called 14.1
The 2 new users (admin and non-admin) contain the 14.2 folder.
I've tried to move tha 14.1 folder of my main account on the desktop ... it still doesn't launch.
I also tried to copy the 14.2 folder from the admin account to my main account ... no success!!
I really don't understand why the only account where I cannot launch AE is my main account.