One thing different in Ubuntu and Windows is when you have multiple drive/partition, in Windows, it will automatically mount all your drive/partition and you can easily access them through the My Computer; but in Ubuntu, it only mount the main drive (the one Ubuntu is install in it) by default. If you wish to access files on another drive/partition, you will have to open it or mount it. There is not much problem about that one, but the problem comes when you have auto started program that need to use the files in the non-primary drive. For me, the problem happen when I use Dropbox. I store my dropbox files in my Data drive, and when it auto started when Ubuntu started, it will pop out an error saying that it can't find the dropbox folder, because the Data drive is not yet mounted. In this guide, I will shows on how to easily enable the auto-mount for your non-primary drive.
1st step is to go to Ubuntu Software Center, and search for an application called MountManager. Install it.