Thanks for the replies guys, I finally got Xport 360 to copy all the files over to my PC HDD. I went to use Xport 360 to drag and drop files onto the new 250GB and I just got the "Cannot move here" cursor again, so I did some googling again and believe it or not Datel had it on their FAQ but called it "Drag and drop" while I was googling "writing to HDD" lol. Sometimes it pays off to be less technical. Anyway, it told me to disable UAC (which I thought I did a long time ago) and so I did, I booted back up to find that Xport 360 literally needs UAC in order to find your HDD. V_V I sat there forever and nothing, so I decided to try Xplorer360 again now that I had UAC disabled, and it worked! I'm so glad, only thing that made me mad is that I copied a backup from my old HDD which had old saves for Assassin's Creed II and now I got to do a whole bunch more missions over again.
But, I've seen people say "This is exactly what happened to me" on here, Maxconsole, and Afterdawn and yet there's not been one "Xplorer360 not working" thread found by google to fix this, I hope this thread helps others that have this problem, thank you all for pointing me in the right direction.