From what version did you upgrade?
If it was OfficeScan 8.0 Patch 2, the firewall service may not have properly started.
If it was OfficeScan 8.0 Service Pack 1, you might see in the management console that the Common Firewall Pattern version is listed as "N/A" or "0".
If either of these is the case, do the following to resolve the issue:
1. Stop the Cryptographic Services from the Microsoft Management console.
2. Go to C:\Windows\system32 and rename the catroot2 folder to "oldcatroot2".
3. Start the Cryptographic Services.
4. Open a command prompt and run the following commands:
a. regsvr32 wintrust.dll
b. regsvr32 netcfgx.dll
5. Restart the computer.
I am a Trend Micro employee. My comments and advice come from my personal knowledge and experience. I’m happy to volunteer what I can to help others have a great Trend Micro experience.
