I must (and do) acknowledge McAfee's assistance in putting me on the road towards this solution. They didn't get all the way to the exact fix though, so I have given them the details and I hope they will include it in their knowledge base for future support contacts.
But for those who use TekTips as their first port of call...
Symptoms:
You have both McAfee Privacy Service and Personal Firewall Plus installed. (For me they were installed on XP Pro SP2, but I guess it could cover NT and 2000 too).
In Privacy Service, you have set the option to "Let me use McAfee Personal Firewall to manage Internet programs".
All of a sudden, your internet browser and mail client stop being able to connect. They just say they cannot find the host address (eg If you try to ping a website name from the command prompt, the error says it could not find the host.
However you CAN still browse websites if you type their IP address into the address bar of your browser, and you CAN ping websites by IP address.
If you stop the Privacy Service (but leave Personal Firewall Plus and the other McAfee services running), browsing works again.
Likely Cause and Fix:
For some reason, Privacy Service has decided to start blocking "Generic Host Process for Win32 Services" (svchost.exe), even though Personal Firewall Plus is set to let it connect.
All you need to do is remove the entry from the Privacy Service list.
Detailed Instructions:
Open the configuration for Privacy Service (right-click the M by the clock, choose 'Privacy Service' and then 'Open Privacy Service').
Click the 'Security' icon on the left, then click the 'Control what programs can access the internet' link on the right.
In the list of Internet Programs, you will probably see 'Generic Host Process for Win32 Services (svchost.exe)'. If not, then your problem is something different from this.
If it is listed, clear the "Let me use McAfee Personal Firewall to manage Internet programs" box. Then highlight the line for svchost.exe and remove it. Finally, check the "Let me use..." box again, click OK and close the Privacy Service window.
But for those who use TekTips as their first port of call...
Symptoms:
You have both McAfee Privacy Service and Personal Firewall Plus installed. (For me they were installed on XP Pro SP2, but I guess it could cover NT and 2000 too).
In Privacy Service, you have set the option to "Let me use McAfee Personal Firewall to manage Internet programs".
All of a sudden, your internet browser and mail client stop being able to connect. They just say they cannot find the host address (eg If you try to ping a website name from the command prompt, the error says it could not find the host.
However you CAN still browse websites if you type their IP address into the address bar of your browser, and you CAN ping websites by IP address.
If you stop the Privacy Service (but leave Personal Firewall Plus and the other McAfee services running), browsing works again.
Likely Cause and Fix:
For some reason, Privacy Service has decided to start blocking "Generic Host Process for Win32 Services" (svchost.exe), even though Personal Firewall Plus is set to let it connect.
All you need to do is remove the entry from the Privacy Service list.
Detailed Instructions:
Open the configuration for Privacy Service (right-click the M by the clock, choose 'Privacy Service' and then 'Open Privacy Service').
Click the 'Security' icon on the left, then click the 'Control what programs can access the internet' link on the right.
In the list of Internet Programs, you will probably see 'Generic Host Process for Win32 Services (svchost.exe)'. If not, then your problem is something different from this.
If it is listed, clear the "Let me use McAfee Personal Firewall to manage Internet programs" box. Then highlight the line for svchost.exe and remove it. Finally, check the "Let me use..." box again, click OK and close the Privacy Service window.
