I suspect your anti-virus is "quaratining" the file with a "false positive" identifiction of a Trojan. See the other help tickets, as this just recently started with Norton and McAfee. Both have replied it is their problem, but it won't be fixed until their next virus definition file release.
You can re-install the Direvctory software by:
If you still have problems, verify yoru anti-virus isn't "quaratining" the file. Yiou may need to "restore" it and be sure to exemot it from the virus scan.