Since I've upgraded my RAM into 12GB, I'd like to take advantage of it on Windows too. Previously I have Windows 7 32 bit ultimate. And for RAM availability I upgrade (clean install of course) my Windows Bootcamp to 64 bit. Now I always have this error code: 0x80070005 in the middle of setup, in "Extracting files" step. I never have problem with 32 bit installation, it was always smooth and sound. But 64bit would never install on my iMac. Mine is 2011 model with 3.4GHz i7 with 6970M 2GB. I'm using Lion, so Bootcamp has been 4.0. But I've tried install 64bit on SL, gave the same error code. Any tips or step I missed? Please help, I'm hesitant to going back to 32 bit since my RAM going to be obsolete on it Any help please? Bad DVD? Well I've tried several copies.. still the same. I've seen others has been fine with Windows 7 64 bit on BootCamp. No reason that 64 bit is not supported, right?