thx Tom
I found:
gdimgplug.dll V. 1.7.0.32 in my application directory
gdpicturepro5.ocx V. 5.13.0.5 in my windows system directory
in no other directory I found these files
I run my application and try to delete these files ... its not be possible ... so I think, they are in used.
the problem ist allways exists
