A Folder Will Not Delete At All - Filename, Directory Name

Folder on my external hard drive will not delete at all. it says " the filename, directory name, or volume label syntax is incorrect". i have also entered the file an tried to delete the things inside but they say " cannot delete file: cannot read from the source file or disk". It happen wen i used the file(temp folder) for emule. it is a virus i suppose but the folders say it has no bytes to them but wen i see the size of the whole folder it's 24.5 GB of space.