$ dir /b ~$
File Not Found
$ echo > "~$"
$ dir /b ~$
~$
$ perl -e " unlink '~$' or die $!"
$ dir /b ~$
File Not Found
$ notepad > "~$"
$ dir /b ~$
~$
$ perl -e " unlink '~$' or die $!"
Permission denied at -e line 1.
$ perl -e " unlink '~$' or die qq/ $! \n $^E / "
Permission denied
The process cannot access the file because it is being used by another process at -e line 1.