Win 10, explicitly because I run CAD software (Autodesk Inventor specifically at home) and the linux compatibility workarounds like wine have not worked properly the last few times I have tried them. I could dual boot but I just don’t feel like putting the time in to set it up and use it anymore.

Newer versions of office allow for “sharing” the excel sheet via a link but I don’t know if they allow track changes to be on/visible for the “live” edits.