In a computer-implemented method for maintaining unallocated hosts of a pre-configured hyper-converged computing device at a baseline operating system version, a plurality of hosts of a pre-configured hyper-converged computing device is managed, where the plurality of hosts are allocable to workload domains, where the plurality of hosts each have an operating system version within a range of supported operating system versions, where unallocated hosts of the plurality of hosts are maintained within a pool of unallocated hosts, and where the unallocated hosts of the pool of unallocated hosts have a baseline operating system version of the range of supported operating system versions. A new unallocated host is received at the pre-configured hyper-converged computing device for inclusion to the pool of unallocated hosts. An operating system version of the new unallocated host is determined. Provided the new unallocated host has an operating system version other than the baseline operating system version, the new unallocated host is updated to the baseline operating system version. The new unallocated host is released to the pool of unallocated hosts for allocation to a workload domain.