I hope you are not using IE6 anymore and hence you do not have to read on. Skip this post please!
Oh! You are still reading. Well for my work, I had to test our webapp in IE6 as well. While doing so, I noticed that IE6 was extremely slow ( Okay! I am not comparing with firefox/safari. only with IE7 ). I started to wonder about it until I came across MS hotfix for IE6 ( http://support.microsoft.com/kb/942840 ). After updating IE6 with this hotfix, IE6 was comparable to IE7 ( and infact I found it faster. Again, not comparing with firefox ).
So if you still using IE6, you may consider this hotfix for faster IE6!
Infact why are using IE6? Go on, upgrade! get IE8 or firefox…
Yesterday when I tried to run Apache web server in my system, it failed to stop. All I could get was an alert message from Apache Monitor was “Requested operation has failed”. No description, No error code, absolutely vague error message.
I tried running apache directly from the installation location and it threw quite descriptive error.

Duh! Looks like apache server failed to get ownership for port 80. But I had not installed any other web server, so which application is using port 80 ? Here is what I did to find out
1) Execute netstat -na -o command ( netstat guide )and search for port 80. The last column in result would indicate the process id for the application which is blocking the port
2) Execute tasklist with find command and see which application is that

Oh! As you can figure out from screenshots, skype was using port 80. So if you are facing similar kind of problem, you need to configure skype first .
Launch Skype. Click on Tools -> Options -> Advanced -> Connection. You would notice a checkbox for using port 80 and 443 as alternatives for incoming connections. Uncheck it, save and restart skype.

Apache did start after configuring skype for me. This is just one of the case why apache throws up such error which I faced.
There could be scenario where your firewall configuration is blocking apache or you configuration file is corrupted.
Alternatively, you could configure apache to listen to other port instead of port80. Search for Listen in httpd.conf and replace port ( do not use standard ports though! ).