You will have to contact your Value Added Reseller for help with that.
If you are talking about files that you made when you were using the educational version, then Glenn has given you the correct advice.
If you are having problems with files that you made since you started using the professional version, then it is likely that you have a problem with your templates. If your templates were made with the educational version and then revised for use with the professional version, they are quite likely to still have the educational watermark. You either need to make brand new templates or, possibly, have your VAR modify the template files the same as any other files made with the educational version.