Just downloading the file isn’t enough. Corrupted ISOs lead to “Invalid signature” or “Kernel panic” during boot. VMware publishes checksums for all legacy ISOs.
Running ESXi 5.1 in a production environment is discouraged because it no longer receives security patches or bug fixes. Installation Requirements download esxi 5.1 iso image
Before deploying ESXi 5.1, it is essential to understand its support status: August 27, 2012 End of General Support August 24, 2016 End of Technical Guidance August 24, 2018 Just downloading the file isn’t enough
Despite the age, VMware keeps a "Patch Portal" for paying customers with active support contracts. 2018 Despite the age
To successfully run the ESXi 5.1 installer, your hardware must meet these minimum specifications: