My macintosh won’t start after trying to install Wireshark

Hello,

I have a MacBook 10.5.6 and after tried to install Wireshark It asked me to put a folder to my "OpenonStartup" mac folder, after this I restarted, and my computer warned me to only allow that WireShark Foldar into my StartupFolder if I trusted it. I click "Allowed" and prompted for a Restart.

After the restart, I will get the greyish screen with the apple for like 5 seconds, then my computer will turn back off.

I've tried to start it several times, but with no gain.

Is this a common problem? Can you guys help me solve it? Thanks in advance.