NetLogo is fastest and most reliable if you use IBM's 1.1.8 Java Virtual Machine.  If you downloaded our installer that includes a Java VM, then the default (and highly recommended) choice on the next panel will install the IBM VM and configure NetLogo to use it.  (The VM will be installed for the use of NetLogo only and will not affect other programs on your system.)

If you did not choose the download option that includes the VM, you should probably go back and choose it.  (Unless, that is, you have already separately installed the IBM 1.1 VM on your system yourself, or wish to use a different VM.  If so, you may choose it in the next panel.)
