I'm about to lose my mind doing all this.
You get one thing working and then something else doesn't.
Ok, under sound devices i have SE49 (my keyboard) and "high definition audio device". It tells me the latter is working properly. I can hear stuff when i run audio anyway, it just seems that Reaper wants to play silly buggers. I had it set to use the WASAPI audio driver which was producing low latency results and was fine. But I couldn't get my keyboard to work.
However that now seems to be (for now) solved after I deleted the driver i'd installed to get it to work. It should be able to run just as plug and play anyway.
Unfortuantely WASAPI stopped working from an input perspective. I got an error message saying 'can't find input device' with only the 'default input device' to use which wasn't getting any sound.
Although I have headphones plugged in the laptop seems to have two separate settings regardless so having them plugged in doesn't override the output, you have to, if possible, choose headphones. That would be fine if it didn't keep flipping between those two choices on its own.
So now I've chosen DirectSound as my audio device and i'm back to having latency.
I don't really understand ASIO as it doesn't seem to work at all. I don't know what input/ouput option I should choose and messing around with all these options seems to affect other options. I can't just go back to WASAPI either, because it doesn't seem to work. I've no idea how any of this works or why it's happening. It makes no sense and to the best of my knowledge i have not uninstalled or deleted anything