ESXi 5.5 was designed for older hardware. Check the VMware Compatibility Guide to ensure your CPU and NIC are supported.

Ensure virtualization technology (VT-x or AMD-V) is enabled in your server’s BIOS.

If you are planning to deploy ESXi 5.5 today, you must be aware of its support status: September 19, 2018. End of Technical Guidance: September 19, 2020.

Because it is past its lifecycle, ESXi 5.5 does not receive security patches , bug fixes, or maintenance updates. It is highly vulnerable to modern exploits and should only be used in isolated, non-production labs. Key Installation Steps

After installation, use the Direct Console User Interface (DCUI) to set a static IP address and hostname. Should You Still Use ESXi 5.5?

Major hardware vendors like Dell , HP , and Lenovo often host customized ESXi 5.5 images designed for their specific server hardware. These are typically the easiest "official" versions to find.

While Broadcom has shifted its focus to subscription-based models like VMware Cloud Foundation, some legacy paths still exist for finding this specific installer:

You can find specific builds such as ESXi 5.5 Update 2 or Update 3 on their support site.

If you have an existing account or "entitlement" from a past purchase, you can try searching the Broadcom Support Portal. However, older versions are frequently hidden or restricted to those with active support contracts.