[barrkel]

Windows interrupt priorities are called IRQLs, see https://blogs.msdn.microsoft.com/doronh/2010/02/02/what-is-i... for a discussion.

Mostly PnP decides the levels, unless you have multiple IRQs and you need to specify the priority.

[xorblurb]

That very page makes me think device drivers don't choose their DIRQL. Any more precise pointer to how they can do that?