I'm looking for a term that collectively describes both software and hardware. Doesn't have to be a single word but it would be preferable.
It depends on your context to a great extent, but common IT parlance would just refer to "a system". It would be unnecessary to prefix this with "computing", "IT" or similar if the context is clear, e.g. we lost connectivity because the system was down.
Ecosystem. When used for technology, the word describes not just hardware and software within or related to a single device, but across multiple devices, services, or product lines.
For example, one could describe phones, tablets and other devices running the Android operating system, as well as the apps that run on those devices, and compatible accessories as constituting the 'Android ecosystem'.
Going to go with technology as it encompasses everything about computers and gadgets in general.
Computer. Edited: I suggest this because all functional computers comprise hardware and software.