Trying to fix a problem on my MacMini, running OsX 10.5, I deleted the file /library/intego/virusbarrier.bundle and now I cannot launch anything at all: applications, web, nothing works. I tried to put the file back, but the Library directory is locked. I cannot reinstall the system because my DVD drive is broken. What can I do to put that file back?Is it possible to unlock the directory?