A discarded Windows laptop is ideal for use with Linux. That’s what this Managing Director of an IT company has been doing for over a decade. My desktop PC is a customer cast off from a good five years ago. I slapped in an ageing Nvidia el cheapo card to get two monitors running. My laptop is a cast off from one of my employees - I simply opened it up and moved my M.2 card into it.
I do run ESET on my Linux gear to show solidarity and to show that Linux really is rather more resource friendly than Windows. I login to AD and I use Evolution with Kerb to access Exchange for email. I have the same “drive mappings” to the same file servers too and so on and so forth.
I used to teach word processing, spreadsheeting and databases n that for UK govt funded courses, I’ve written a Finite Capacity planner for a factory in Excel (note the lack of In-). I still find people who have no idea how decimal tab stops work or how to efficiently use styles. I can confidently inform you that Libre Office is just as good as MSO. They both have their … issues but both work pretty well.
Kids are easy. Adults are a pain! KDE has a lot of educational games ready to go out of the box.


Errm, Wireshark. Please bear with me.
Wireshark is a shining example of an open source project completely and utterly crapping on the closed source competition. As a result we all benefit. I recall spending a lot of someone else’s money on buying a sort of ruggedized laptop with two ethernet ports to do the job back in the day.
Nowdays, I can run up a tcpdump session on a firewall remotely with some carefully chosen timings and filters and download it to my PC and analyse it with Wireshark.
OK, all so convenient but is it any use?
Say you have a VoIP issue of some sort. The PCAP from tcpdump that you pass to Wireshark can analyse it to the nth degree. Wireshark knows all about SIP and RTP (and IAX) and you can even play back the voice streams or have them graphed so you can see what is wrong or whatever. That’s just VoIP, it has loads of other dissectors and decorators built in.
So what?
The UK (for example) will be dispensing with boring old, but reliable, POTS (Plain Old Telephony System) by 2025. Our entire copper telephony and things like RedCare (defunct soon) will go away.
We are swapping out circuit switching for packet switching. To be fair, a lot of the backend is already TCP/UDP/IP that is shielded away from us proles. When SoGEA (Single Order Generic Ethernet Access) really kicks in then the old school electric end to end connection will be lost in favour of packet switching, which never fails (honest guv).
If you are an IT bod of any sort, you really should be conversant with Wireshark.