The https://bitcoin.org/en/download page suggested downloading the Windows 64bit Bitcoin Core.  It also has the following suggestion:
"If you know how to download a torrent file, you can speed up this process by putting bootstrap.dat (a previous copy of the block chain) in the Bitcoin Core data directory before starting the software."  It had the imbedded link to download the torrent. After syncing up and receiving my .02 BTC I backed up to a thumb drive.  Then, later, I tried to Send a small piece of that .02 BTC.  That's when it asked for my Passphrase (not password).  I sure don't remember ever setting it.  I will try to duplicate a download on another computer to see if it suggests a passphrase.

So, I did backup my wallet.  How would I restore it?  If I uninstall the program and download a fresh copy, do I put that backup wallet file somewhere?  I didn't see an "import" capability.

Thanks for any info. 

I downloaded the latest Bitcoin Core Wallet V. 0.9.1.0 a few days ago and did not launch it.  I then downloaded the current .dat file via P2P network and placed it in the proper directory.  I started up and it all sync'd up rather quickly.  I then transferred .02 bitcoin from my Coinbase wallet and it went fine and shows up as my latest transaction. Next, I backed up my wallet to a thumb drive.  A few days later I tried to send a token amount to someone as a test.  It asked for a passphrase.  I'm sure I never gave it one before and the encrypted lock is on.  Am I out my fortune of bitcoins? 

I am glad I did not transfer a whole lot to this wallet.

Thanks!