When browsing the download list, you will see file names like ESXi-7.0U3s-21686939-standard.zip . It is important to understand what you are downloading:

Once you've downloaded the patch, follow these steps to install it on your ESXi 7.0 host:

Following Broadcom’s acquisition of VMware, the process for downloading ESXi 7.0 patches has moved to the Broadcom Support Portal

Click the "Terms and Conditions" link to enable the agreement checkbox. Once accepted, you can download the Offline Bundle (.zip) for manual patching or the ISO for upgrades. 2. Alternative: vSphere Lifecycle Manager (vLCM)

From the "My Downloads" section, select "VMware" from the division menu and search for vSphere .