If the first few characters of the filename gets changed to an unprintable character the file can show this behavior. If this is the case then deleting the files via the command prompt is an option. (I'm assuming you're a Windows user.)
1. Open a command prompt window
2. Switch to the drive in question. For example to switch to the E drive you would type E: then press enter
3. Change to the folder containing the files with the CD command. For example, to change to the folder My Music you would type CD My Music then press enter
4. To see the files in this folder type in DIR then press enter.
5. To delete files you need to use the DEL command. Warning! Files deleted in this manner will not go to the Recycle Bin. They will be permanently deleted
- For example, to delete a series of files named foofighters1.avi, foofighters2.avi, foofighters3.avi etc., assuming the first character of the filename got messed up, the command would be DEL ?oofighters?.avi
The ? in this case is a wildcard that means any character. You might need to get creative with the placement of the question marks. You can use multiple question marks in a row if needed.
Be careful how you format the wildcarded filenames or you might accidentally delete something important. I suggest doing a DIR ?oofighters?.avi first and see if it lists just the files you want to delete before doing a DEL ?oofighters?.avi