I recently purchased Trend Micro PC-cillin Internet Security which includes a Personal Firewall which disables the Windows XP Firewall, which is OK to do.
Since installing this product, my connection speeds have varied a great deal, from snail pace to supersonic speed.
The real deal breaker is that the Event Log continually shows that the Personal Firewall service is crashing. Initially I was just restarting the service.
I contacted Trend Micro support several times and the "solution" was always to re-install.
Today I decided that a re-instal just hid the problem for a time, it was never uncovering what was wrong (my laptop, my setup, a bug, etc)
After snooping around I found several log files in the Programs/Trend Micro/InternetSecurity/Log folder,
and there was a continual error with verbage including "CoExistance" and "The service has discovered another firewall".
There was no other firewall, because the XP Firewall was disabled.
It turns out to be the Linksys Router that I use (WRT54G) has a firewall inbuilt (I had forgotten about this rather important feature)
and it was causing the Trend Micro Firewall service to crash because, I am assuming, someone had designed the product not to "like" 2 firewalls running in tandem.
Strange that Windows XP Firewall does not have such a problem with the router firewall.
I think the only options are :
1 - Install again without the Trend Micro Firewall portion
2 - Install again with Trend Micro Firewall but not enable
3 - Simply disable the Linksys inbuilt Firewall?
Option 1 would seem less practical because what if I hooked up directly to the DSL modem?
Option 3 would be easy, but perhaps I may have visitors who bring their laptop with them and Trend Micro is not installed on those particular machines.
So it looks like Option 2 wins the day. A quick phone call to Trend Micro Support confirmed that Trend Micro PC-cillin has conflict issues with Linksys Routers (yet the inbuilt Windows Firewall worked well with the very same router before I purchased TM PC-cillin), why could TM not do the same? And after reading once again the help screens for the TM Firewall, and the ability to have different profiles for different circumstances as one moves from home to Starbucks to a Boeing 777 it now makes perfect sense to go with Option 2, and create a Home Network profile with no Trend Micro Firewall, and create another profile with Trend Micro Firewall for those times I am away from home.
I then found a Trend Micro Solution Detail which said "Check for third party firewall applications installed in the computer (it never mentioned the router), Some users have other firewall programs installed in their computers. In some cases, a third party firewall blocks PC-cillin Internet Security's access to the Internet and causes errors in the update function.
Make sure that PC-cillin Internet Security is given permission to access the Internet then update again."
And there I thought was my solution. Go into the router configuration and simply tell it to allow the Trend Micro Firewall. But alas, the router configuration has no place to do this.
Options to enable or disable the firewall exist, as well as options to block websites by URL, Keyword or Service.
There is no place to allow something to happen.
Has anyone else struck this problem, and if so, what option did you elect to go with, or do you have another method to correct this?