Just installed Windows Live Writer on Windows 8.1 which turned out to be more effort than I wanted because googling for Live Writer takes you to an old installer. You actually need to download Windows Essentials.
Details covered here: http://www.hanselman.com/blog/DownloadWindowsLiveWriter2012.aspx
The next challenge was getting Writer connected to my Blogger account. It tells me the username and password are incorrect, even though I know they are not. Turns out that google are now blocking the old authentication mechanism being used by Writer. You can either re-enable that mechanism via your Google profile page, or, even better, enable 2 factor authentication and generate an app password for Writer.
Writer on Windows 8.1 also defaulted to a very small 6pt font. Simple enough to switch it to something bigger via the toolbar.