Not unless you enabled auto-save in the prefs. in that case you may find some files in your My Documents/Adobe folder, but otherwise not.
Save, save, save or turn on auto-save in the prefs. That's the only to 'save' a project.
First thing to do, is save.
I imported from PP so I forgot to save the AE.
Auto save was on.
However, I was unable to find the My Documents/Adobe folder.
Win 7 has some kind of user folder, but it is full with Adobe folders of all kinds and an .aep could not be found.
A pity there is no Untitled Document safety.