USB Flash Disk

I have copied some files to a USB flash disk from a Window XP and wanted to open it in the same PC to see whether I have done it correctly . This is my first time to do this.

I found the copied files but Window could not open them. (PBF files)

Please advise which soft ware I have to download in order to open the PBF files, or is there any way to open it.

Chinese reply is also appreciated for I do not know Chinese typing.