Windows through virtualisation

Shikid

If you talk about emulation of x86 systems, you could try virtual machine from ELTECHS (https://eltechs.com/product/exag ... eatures-and-prices/) it could perform much quicker than QEMU, though you have to pay for the license (it is licensed per device).
I would recommend to try ReactOS in case you need Windows XP functionality - it is free of use and possible to run even on old & slow processors - https://reactos.org/

pmpp

Hi @y52,   better take a windows terminal services licence on a big PC (better xeon based)  and run armbian+rdesktop on your diskless pi clients. as people rarely use processors at the same time they feel like having their own desktop.