Can't restart my windows side properly to complete installation of Wacom tablet

I have a Macbook with a Windows partition. I'm trying to download a Wacom tablet driver but it can't complete the installation, probably because of the way I have to restart my computer.

I have to hold down the 'option' key to make sure it restarts back to Windows. If I don't, it'll go back to the Mac side. I've tried both so far but the installation still isn't complete.

help pls ._.