is it possible with Xojo on Windows to record a microphone to a wave File?
For the recording part you can use the BASS library. Simple demo here https://forum.xojo.com/conversation/post/183708
The download bassRecGL should work on Windows but you'll also need to find and install libbass.dll (or whatever it's called).
The demo just records to a short, temporary buffer for drawing. For long, indefinite recordings I use an array of 10MB Memoryblocks. As new data comes in copy it to the current Memoryblock and when it fills up append another Memoryblock and begin writing there.
But there may be functions in BASS that record directly to a file.
If you do need to write the file yourself see here https://forum.xojo.com/23110-how-to-write-wav-or-aiff-data-from-binary-stream
For some € the MBS plugins have functions for audio recording (and writing I assume).
The PortAudio library is another possibility but I haven't used it.
There should be functions built into Windows you can declare to but I don't know them.
In short you'll need declares or a plugin to get audio recordings.
here is the good archive link