could not able to copy 'obj\debug\projectname.exe to bin\deb

Question

Hi friends i have two issue in my project.

1.Error143Could not copy "obj\Debug\LibrarySystem.exe" to "bin\Debug\LibrarySystem.exe". Exceeded retry count of 10. Failed.
2.Error144Unable to copy file "obj\Debug\LibrarySystem.exe" to "bin\Debug\LibrarySystem.exe". The process cannot access the file 'bin\Debug\LibrarySystem.exe' because it is being used by another process.

I have  tried with add the following in the build event.

if exist "$(TargetPath).locked" del "$(TargetPath).locked"

if not exist "$(TargetPath).locked" move "$(TargetPath)" "$(TargetPath).locked"

it worked for me once. but next time same error occur. how can solve this problem.