I don't know about the partitioning of your drve, but if it is making a funny sound, I would immediately backup whatever you need as your hard drive might be about to fail. I had a hard drive [physical] failure about 4 months ago and before it stopped working, I had noticed it making some funny noises....then nothing...it stopped working completely. The bios would not recognize it and it was dead...all gone. I could have had it all recovered for like $1,300.00 but I just took the loss and got a new drive. I had most of the stuff backed up anyway.
Just a tip...it might save you some time if you are gonna have two OS's you might as well have 2 hard drives...in case one dies.