Till yesterday everything was fine to my localhost. But from yesterday, localhost is not opening. It's saying "Unable to connect".

I tried number of time to start the Apache on XAMPP, but its saying message that busy. The port 80 is busy, I hope.

For testing, I enabled Team viewer port 80, and it was easily loading on localhost with message that "Teamviewer is using port 80".

And even I can see that in 'cmd' in Windows XP-SP3 with command netstat -o -n -a | findstr 0.0:80, that the output is TCP 0.0.0.0:80 0.0.0.0:0 LISTENING 3720.

But when I am freeing the port 80 from team viewer, then neither Apache gets started from XAMPP control panel nor the command netstat -o -n -a | findstr 0.0:80 returns anything.