I have a server (Server 2003 Web Edition) that hosts a VNC remote support site using Apache that has been working well for years. All of a sudden, it started what amounted to a denial of service to the other computers on my network. I stopped a lot of services and things were normal. I assumed I had hit on the right thing but not sure what that was. Worked fine for months. Now, after running the latest Microsoft Updates (stupid!) over the weekend, the problem is back again. I have figured out that when the httpd.exe process starts to use CPU, then the NIC shoots up to 98% network utilization and I lose Internet on my network for a couple of minutes. If I manually kill httpd.exe, then immediately things go back to normal. Problem is, I need the Apache running for the VNC site to work so I can't kill it completely. Help!
Can you let me know which antivirus you are using ?
Please go through below link where it says you need to modify httpd.conf file,
http://www.sitepoint.com/forums/showthread.php?861373-Apache-using-100-resources
http://www.symantec.com/connect/forums/httpdexe-using-100-cpu-after-upgrading-sep-12-ru2-mp1-sep-12-ru3
http://www.symantec.com/connect/forums/httpd-running-100