Stay away from Bitlocker. I used it i the past, and lost my data because I didn't realize that I needed to export the key. The MS Bitlocker encryption key is unique to your windows install. IE: it's not a password you enter. If someone steals your laptop, they have access to your encrypted info. If you have a backup of your encrypted files, your HDD crashes, and you do a fresh install of Windows on a new HDD, your backup is worthless. Maybe the NSA can recover your data, but you can't.
I use Winrar to compress and archive files and them PW protect them. It works for my purposes, which in the grand scheme of things aren't important.
If you're using Bitlocker, don't. un-encrypt your files and use proper encryption software.