Batch DRM removal with FairUse4wm: UnDRM multiple Windows Media files at once

hey there...i got one problem left ! every thing is fine with the undrm process for every file.....i got license and it works very well..thx to u!
but to undrm the file i need to open the file with wmp and then it automatically tells me the license is installed and ready to play. then i can undrm my file with out problems..the only thing is i got so many files to undrm..and cannot add all of them to FairUse4WM at once..since it tells me that besides the first one with the opened file in wmp....so what can you suggest to me!???
thx for help