cacls

i edited admin account(ppar) i used ” cacls finame /t /p ppar:n”. during logged in this admin account ppar.
But now i cann’t edit it again by typing “cacls filename /t /p ppar:f”
I opened the file with window explore but i got the error message (acced denied). i logged out ppar and logged in administrator and then try to open it but i got the same error message .
how can i access it. resolve 4 me, please.
i used windows xp sp 1.