Short answer to your question - Yes, you can access hard drive after you boot using live CD.

Long answer - You will find shortcuts for existing disk partitions on your desktop. For example, if you have 1 IDE hard drive (referred as /dev/hda) and it has 2 partitions on it, you will see 2 shortcuts called /dev/hda1 and /dev/hda2. You can just click on those shortcuts to browse files on those partitions.