Apache Friends Support Forum

I start xampp_start.exe and apache doesn't start. Then I run apache_start.bat and I have an error:
(OS 10013) Trying to access to a socket not allowed : make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
unable to open logs
Apache could not be started.
I'm using vista as an administrator (I use administration account).
Why I can't start apache?
Mysql runs well.
I've tried to run xampp-portcheck.exe but it doesn't run too. It comes a "vista window" saying openports.exe failed.
Thanks.

IIS isn't running in my system. I've looked up in task manager and isn't there.
I've runned wampp-portcheck.exe as administrator and occurs the same error (openports.exe failed). I've also runned netstat -ano and nobody uses 80 PID.
I don't have skype installed.
So I don't know what is failing.
Thanks for your answer.