Is it possible to do drawings in Procreate but later transfer those drawings to Illustrator on Windows computer?
I would assume that you can export several file format out of Procreate. It might even work as a PSD. If nothing else works, JPG should be there. Then you can place it in Illustrator. As far as I know, Procreate cannot output any vector artwork.
Procreate doesn't create any vector-based artwork. You can export layered Photoshop PSD files out of Procreate, as well as several other pixel based formats (like PNG, TIFF, etc) to place in Illustrator. I personally would only use a Procreate sketch within Illustrator as a source image for hand-tracing clean vector artwork.
On the Windows platform I just tend to use Photoshop in conjunction with a Wacom tablet. If or when I need to trace that image I just place it into Illustrator, lock the sketch image down on one layer and then hand trace clean vector artwork over the top of it on another layer.
These days I'm not too fond of sketching using a Wacom tablet. That's because Wacom allowed its drivers to incorporate Windows Ink. There really is no way to underestimate how much I absolutely hate the Windows Ink feature. Windows Ink has to be turned on in the Wacom tablet's properties in order for the stylus to have any pressure sensitive capability. But if Windows Ink is turned on I basically lose most of the normal mouse functions in the pen stylus. I can't do normal animated zoom in/out functions in Illustrator because the left mouse button behavior is altered. If I click into a text entry box with the Wacom pen I'll see a pop up dialog box insisting that I hand write what I want to put into that text entry box. Never mind that my computer has a ****king keyboard that works 894,989,893 times faster than writing things by hand! It is one of the most blatantly stupid things ever. What's the next big advance in technology? Sending SMS text messages via Morse Code? Keyboards were invented for a reason. And there is no way to disable that pop up without turning off Windows Ink and losing pressure sensitivity. Wacom really really needs to fix that nonsense. And Microsoft needs to work on that as well. My computer is not a Galaxy Note 5 phone!
So now I pretty much have to rely on an iPad and Apple Pencil if I want to draw artwork with pressure sensitive strokes. Procreate on the iPad is great at that. The iPad versions of Illustrator and Photoshop are not so bad either; although I wish they had more of the same kind of smoothing controls of Procreate. I can beam artwork from the iPad version of Illustrator to the Windows desktop version with only a couple clicks.
BTW, the iPad has the option to allow text entry via handwriting from the Apple Pencil. But the feature is (smartly) turned off by default. And it's easy to toggle on/off in the iPad's settings. Microsoft likes to copy a lot of things from Apple. Here's one feature they desperately need to copy. Cuz for the time being Windows Ink really really sucks.
Fresco is available for Windows: https://helpx.adobe.com/fresco/get-started.html
Personally I don't like sketching in Illustrator that much. Exception: on the iPad. The Illustrator pencil on the iPad is great. Biut Fresco is a nice thing as well. And: it can also do vector paths and also export them.