Begin by downloading the latest Windows Miner from btcsube's Github:

https://github.com/btscube/steem/releases/download/v0.11.0/steem-win-x64-011.zip
After the download finishes, unzip "steem-win-x64-011"
Navigate into the newly created "steem-win-x64-011" folder and double click "steemd.exe"
Close the command prompt

Download the latest blockchain:

http://steemitup.eu/witness_node_data_dir.tar.gz
After the download finishes, unzip "witness_node_data_dir.tar"
Navigate into the newly created "witness_node_data_dir.tar" folder
Once again, unzip "witness_node_data_dir"
Copy the newly created "witness_node_data_dir" folder
Go back to the "steem-win-x64-011" folder and paste the "witness_node_data_dir" folder here
Allow the folder to be overwritten

Right click on "config.ini" and choose "Edit" (I prefer to use Notepad++ for this)
Locate "# P2P nodes to connect to on startup (may specify multiple times)" and paste the seed-nodes found here: https://steemit.com/steemhelp/@steem-id/updated-steem-seed-node-list
Locate "# Endpoint for websocket RPC to listen on" and put "127.0.0.1:8090" as the rpc-endpoint rpc-endpoint = 127.0.0.1:8090
Locate "# name of witness controlled by this node (e.g. initwitness )" and put your steem account as the witness witness = username
Locate "# name of miner and its private key (e.g. ["account","WIF PRIVATE KEY"] )" and put your account and WIF Private Key as the miner miner = ["account","WIF PRIVATE KEY"]
Locate "# Number of threads to use for proof of work mining" and put the amount of threads you would like to dedicate to Proof of Work mining mining-threads = 4
Save and exit the editor