Windows Recall does NOT require NPU hardware to run. Currently Recall has been tested on Windows 11 with only a CPU and it seems to be fully operational. Of course performance is not as good as with an NPU. I believe Microsoft will try to push AI to local computing by only enabling on computers with NPUs to begin with. In the future it will most likely be able to be enabled on PCs which does not have an NPU but with a warning of bad performance in front of it.