under windows-ntfs if you special characters in a filename… you can get into trouble deleting them (from command prompt it should always work)

under linux-ext3 you can run into similar problems if a filename (for whatever reason) contains „–“ (two minuses)

to remove them go:

rm -- --testings.html

The — option tells rm to treat all further arguments as file names, not as options, even if they start with -.