if you're using parallels and full bootcamp then you're making it 100% more troublesome for youself then it needs to be
bootcamp is running windows directly on the hardware this give full memory and cpu and 3d video game power
running windows in parallels is running a virtual machine where one can't run powerful games and the like but one can have it in a window and change fast between osx and windows
parallels as the only virutal machine (as far as I know) support not have the operating system as a file on the osx harddisk but can access a bootcamp parition as virtual machine but without the benefits bootcamps provides
it's a service parallels provide for those who want both to play games in normal bootcamp and sometimes use windows in a virutal machine
just install it like a normal virtual machine and you need not worry about bootcamp drivers and the likes
plus it would mean that the windows part would be a part of the timemachine bacup of osx
which it is not when it's in bootcamp
Then read the guide in Boot Camp Assistant and thru the support page, with FAQ, HOW TO and more.
VMware Fusion is also a dual boot + VM product.
Make sure you are using the current versions.
Usually ask on Parallels first? and do Windows updates natively (aka dual boot when it is a Windows only) aka "Boot Camp" which can mean drivers, control panel, partitioning, or some use it to mean "Running Windows on a Mac natively" One word, too many uses.