ive tried evrything even the cut and paste on fexplorer but it still wont work how do i fix this thanks

If you have FExplorer, select a picture you want to set as operator logo, hit "Options", then "File" and then "Set as operator logo" (scroll down until you see it) & it is done (the phone will restart).

Then go (with FExplorer) and see what you have in c:\system\Apps\phone\oplogo

still wont work

It works for me. What kind of picture are you trying to use? Operator logos are 97 pixels wide and 25 high.

what format should the picture be?

The operator logo is .mbm (Symbian's multi-bitmap format), but FExplorer can make logos of .bmp, .mbm and .jpg (at least).