Excel cannot access
 

Hi
Very important accounting(which is 26 KB only) excel file is not
allowing me to open the file. I may encrypted this worksheet and immediately
turned into green colour, 6 months later i reinstalled windows XP pro but
this time iwhen i try to open

First dialog box show that : Excel cannot access "file name". The document
may be read-only or encrypted.
Then second dialog box show up : Cannot access "file name".....
i tried openoffice.org but didnt solve the problem.I never used any
password for this file.
I think this excel file ,when i choose the option to encrypt ,it got a
certificate
from windows xp and when i reinstall it ,it can not reach the same
certificate.
ANy idea how to open this important file ?you can write to me
at

Thanks in advance