The following will guide you through the procedure of running a fast sync via geth --fast on Windows OS 10 for Mist.
Step 1: Open command prompt (Not Administrative privileges):
Step 2: Go the file directory for geth which looks like following on Windows OS: ~\Ethereum-Wallet-win64-0-7-4\resources\node\geth
and drag using your mouse the geth file (a) from its location and place it into the command prompt window (b):
Step 3: You would see the following below if you did it properly: path to the geth
edit geth.exe to geth --fast as seen in (a) below.
Step 4:Click Enter and you should observe the following below if successful:
You would begin to see the following set of data as the geth starts up and starts downloading the blockchain(syncing).
You can allow it to run till the blockchain has been fully downloaded, point at which you would see the following below: