You could try creating a folder and moving the files there, then delete the folder.
If that does not work you could try going into DOS and using delete with wildcard characters (?-for any single character, *-for any group of characters). You should do a DIR using the wild card characters to be sure exactly what file(s) will be deleted.
If one or more files is a directory (folder), you will need to use the
Be VERY careful with this command as it deletes the folder and all files contained in it.