it always give error while i try to do so..i use several deleter but they didnt work
Didn't worked in safe mode either I tried every thing didn't work... files are too many so can't unlock each file and delete I want to delete folder which can't be..

What operating system are you using? What type of folder are wanting to delete? If it's located in System folder, it's a part of the registry. I wouldn't advice messing with the registry.
Files and folders that are locked are being used either by the OS or a program using them. Since you restarted in safe mode, I'm thinking it's a system folder.