Overcoming Windows Vista's Shrink Partition Limitations to Dual Boot Windows 7
I've decided to partition the hard drive on my new laptop and install Windows 7 Beta alongside the pre-installed Windows Vista, both 64-bit versions (though this applies to 32-bit versions too). I decided to leave my data where it was (the same partition as Vista) and to shrink this partition and create a new one for Windows 7.
Windows Vista's Disk Management console (type diskmgmt.msc in the Run menu) allows one to shrink an NTFS partition, even the one with Vista on it. However, there are some limitations, namely that it won't let you shrink the end of the Vista partition past the last file in the partition. This might be fine for you, but for me it meant that on my drive with 55GB free, I could only shrink it by 13GB, barely enough space to install Windows 7 and my armada of "required" programs.
I tried Windows' Defragmenter to move these files toward the front of the disk, but that didn't alleviate the problem at all. I then tried two free third-party defragmenters, Power Defragmenter and Auslogics Disk Defrag, but neither helped increase the amount Vista would let me shrink the volume above 13GB.
I did eventually solve the problem thanks to a 30-day free trial of PerfectDisk 10 Professional. I needed to run it in boot mode (where it runs upon restarting the computer) to allow it to defragment some pesky system files and finally I could shrink the Vista partition by 55GB, successfully install Windows 7 on the new partition, and access my data on the Vista partition from either operating system.
I hope this helped you!