%USERPROFILE% working Bad

Hello,
I have a Program that uses by default a .ini file inside this program
directory. But if i want to run personally , for each user , to catch his
personal profiles, like temp directories , etc.. i need to put that .ini
file inside Documents and Settings\%USERNAME%\Windows.

The problem is :
For some users, it works and for other users, it doesn´t works. When it
doesnt work the program uses the default .ini file, causing me conflict of
temp files created by the program when the user run it.
I realized that the %HOMEPATH% for that " working good" users is like:
c:\Documents and settings\%USERNAME% and for the others it is blank. Another
thing i realized is that when i logon with a "working good" user that folder
(%USERPROFILE%\WINDOWS) is automatically created and for the others dont.

There is a way to configure or to correct that specificattions for this
"working bad " users?

Thanks
Leonardo