For anyone looking to mine or witness using a Windows machine here are binaries for the latest release of Steem v0.15.0. Which is scheduled to be in use today November 8th.
http://www.filedropper.com/steemd_1 or steemd.zip
http://www.filedropper.com/cliwallet or cli_wallet.exe
You should be able to use the same witness_node_data directory with config.ini. Just swap out the exe files. I always recommend making backups though. Just in case.
For more info on mining and witnessing check out these links:
https://steem.io/documentation/how-to-mine/
http://cryptomining-blog.com/8168-a-quick-guide-on-how-to-mine-steem-on-windows/
@tuck-fheman/how-to-mine-steem-in-windows
@bitcalm/how-to-become-a-witness