You have looked in the 'legacy' system files. These are leftovers from Windows 3.1, and are kept to allow older programs to function.
The settings for nearly ALL program functions are stored in the system registry.
CAUTION: it is VERY possibleto completely disable your PC with improper registry edits.
It is 'best' practice to back up the registry before editing it.
Before you begin, I recommend that you read the registry guide posted at www.winguides.com
and/or read some of the O'Reilly books on the registry and your version of Windows.
The safest way to set the program window size is to edit the shortcut for each program and set the open full screen for those that you wish to force to open at full size.
Many programs have default settings that will NOT respond to any window size changes that you attempt.
Chas