Thanks Andre! That utility did the trick. That utility was really easy to use. I downloaded the drivers from Adaptec and downloaded the following product from VMware Front Experience: ESXi-Customizer
ESXi-Customizer is a user-friendly script that automates the process of customizing the ESXi install-ISO with drivers that are not originally included. Unlike other scripts and manuals that are available for this purpose ESXi-Customizer runs entirely on Windows and does not require any knowledge of or access to Linux.
After expanding the Adaptec drivers I ran the ESXI-Customizer (4 steps). I added the .vib file from Adaptec, then the utility created a new install ISO for me to successfully install vsphere esxi 5.1 easily. This utility was easier to use than the original instructions from Adaptec to do it the way everyone else does normally.
I highly recommend this utility to everyone who needs to add drivers to vshpere esxi any version including the latest 5.1 update edition.
Thanks again for the free utility. I will make a donation asap on your site.
Ron