APACHE didn't start

Hi,
i have Windows Vista Home Premuim 32Bit,
i installed XAMPP,openning xampp-control click start
and only Mysql start,
Apache wrote:
what to do??
i have Windows Vista Home Premuim 32Bit,
i installed XAMPP,openning xampp-control click start
and only Mysql start,
Apache wrote:
Busy...
Error:Apache service not started [-1]
what to do??