message: Update README_windows.txt
diff: -Bitcoin Core
  +BTG Core
  =============
  Intro
  -----
  -Bitcoin is a free open source peer-to-peer electronic cash system that is
  +BTG (Bitcoin Gold) is a free open source peer-to-peer electronic cash system that is
  completely decentralized, without the need for a central server or trusted
  parties. Users hold the crypto keys to their own money and transact directly
  with each other, with the help of a P2P network to check for double-spending.
  @@ -13,11 +13,10 @@ Setup
  -----
  Unpack the files into a directory and run bitcoin-qt.exe.
  -Bitcoin Core is the original Bitcoin client and it builds the backbone of the network.
  -However, it downloads and stores the entire history of Bitcoin transactions;
  -depending on the speed of your computer and network connection, the synchronization
  -process can take anywhere from a few hours to a day or more.
  +BTG Core (aka Bitcoin Gold Core, BTCGPU) is the original BTG client and it builds the
  +backbone of the network. It is based on Bitcoin Core. It downloads and, by default,
  +stores the entire history of BTG transactions, which includes Bitcoin transactions
  +from 2009 to 2017 (currently more than 100 GBs); depending on the speed of your
  +computer and network connection, the synchronization process can take anywhere from
  +a few hours to a day or more.
  -See the bitcoin wiki at:
  - https://en.bitcoin.it/wiki/Main_Page
  -for more help and information.
  