vSphere Update Manager (VUM) is used to patch both the ESXi hosts and VM Guest Operating Systems. Starting with vSphere Update Manager Version 5.x, patching VM Guest Operating Systems is no longer supported. vSphere Update Manager can be installed on the same machine running vCenter Server, however it is recommended to install it on a separate machine.
vSphere Update Manager 5.5 can only be installed on a 64-bit machine.
Here are the compatible operating systems:
VMware might add/remove compatible operating systems for a new release/update. It is advised ...