I was having a problem getting Tomcat to start through Netbeans.

It kept failing.

Solution:

Tomcat > conf > server.xml

Edit server.xml

Look for:

Code:
<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443" />

Add: server="Apache-Coyote/1.1" to the end of the parameters.

Result:

Code:
<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443" server="Apache-Coyote/1.1"/>