I have never seen W7 even 32-bit take 12GB and MS lists 16GB minimum - and most of those that try have installed and then done updates, and only then cloned the OS removing what they can to trim down a normal install. A VM can be much smaller and maybe half. Not a native install and setup - no page file can also be unstable.
I tend to look for rules and find that threads like ours often only get the details at the end, not up front of what is behind the need or problem or question.
But you know how. And how you use the rest of the drive.
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1. First Boot Camp Limitation – Free Space Rearrangement
Apple released its famous utility for dual-system configurations on a Mac – Boot Camp, which shrinks HFS+ volumes in Mac OS X and prepares a partition for Windows right alongside. One problem with Boot Camp is that you cannot resize these partitions later. If free space on one of the partitions is reduced to critical levels and other volumes still have a large amount of unused space, you get into trouble.
The solution for this situation is to relocate space between volumes with Paragon’s CampTune utility. CampTune rearranges free space between HFS+ and Windows partitions and shrinks existing volumes to free unallocated space on a hard disk, and create new partitions without the need to use Boot Camp at all.
2. Second Boot Camp Limitation – FAT32 Only
Apple Boot Camp does not support the creation of NTFS volumes because Mac OS X does not have the appropriate NTFS driver. Since Windows Vista and Windows 7 can be installed only to NTFS volumes, you will have to reformat this partition during the installation.
An easy alternative is to use Paragon CampTune from the beginning: resize the primary HFS+ volume, create second partition, format it as an NTFS volume and install Windows directly.
3. Accessing NTFS Volumes in Mac OS X
Apple’s Mac OS X operating system has limited support for NTFS volumes; the NTFS driver in Mac OS X can read data only. You cannot change files, copy them to NTFS volumes, create new files, or NTFS volumes – all significant limitations.
However, you can easily bypass these problems with Paragon’s NTFS for Mac OS X driver. It has none of these limitations and provides the same level of NTFS volume compatibility for Mac OS X as it does for regular HFS+ volumes. You can easily manage data on any NTFS volume; create files and folders, and copy data between HFS+ and NTFS partitions. The driver adds formatting support to Mac OS X for NTFS file systems and is accompanied by set of utilities for NTFS volume management, checkup and repair - effectively removing boundaries between two incompatible yet universally used file systems.