Help, reconfigure server

[bobby BOBBY]

ok im using mysql4.1 for the database to host my mesage board, i am an amature web-master by the way, anyway when i set up mysql it ask me how many people was i going to be serving. i used the first option witch was like only use it for testing purposes instead of mass users. anyway my message board gets crushed when more than 4 people are on at once. is there a way for me to reconfigure this without another install? i need it to host many users..