Tomcat is not starting - How to trap the startup error?

[Web master]

Hello,

I am using Tomcat as my server and it was working fine till yesterday. 
Somebody was in my system to install bunch of stuff and after that, when 
I tried to start the server, it starts and the JAVA console comes and it 
disappears in a second,. Since I couldn't see, what was in the console, 
I couldn't figure out, what is causing the tomcat not to start.

IS there any way, I can find out why tomcat is not starting. I checked 
my CLASSPATH , PATH and server.log nothing helps.

Thank you for your time.