This sounds like a corrupt file. How old is your hard drive? This always happens to me with wasted floppies.

MS-DOS seems to be a little more friendly with bad files (when in pure mode, not in a window), but really unfriendly to the user. The commmand for delete is "del folder\file.ext" where the files and folders are no more than 8 letters a piece, and the extension is only 3 letters long. There is always a space between commands and directories.

You could also try reinstalling java from http://java.sun.com, that might overwrite the bad file, but is a lot simpler than learning MS-DOS.

Ad-Aware will kill the ads.

Cheers!