The latest release of Parallels, 1970, does not support booting from a bootcamp partition. The latest beta does, but it is beta and by definition contains untested and probably buggy code.
If you choose to download and install the beta, or wait for the next release, you can create a VM that will use the bootcamp partition. If the bootcamp partition is FAT32, you can access it from a VM to share data, or you can move the data to the OSX partition using MacDrive and access it from both bootcamp and a VM.
If you don't need bootcamp, there are some advantages to moving the installation to a virtual hard disk, mainly that disk usage will be lower since only enough space for your data need be allocated rather than the 50 gig you have set up, and that backup of the VM is a simple matter of copying a couple of files in Finder. The next release (as well as the beta) will provide a tool to aid in doing this. The simplest alternative is to create a new VM and install whatever you need, time consuming as that may be.