Dual-booting all versions of Windows and Linux
Dual-Boot another Windows 7 on a Windows 7 computer
Last reviewed: July 2009
This guide shows how to correctly and safely create a natural dual-boot of Windows 7 with a second Windows 7 on a computer with Windows 7 already installed. You can then run either of those two Windows by selecting one from a menu during bootup. No data loss will occur and a third-party boot utility is not used.
In this procedure you need to shrink the Windows 7 drive to make room for the new Windows 7.
32 and 64-bit versions of Windows 7 Home Basic, Enterprise and Ultimate were used in testing so this will also work with Windows 7 Premium and Professional. The computer used was a 32-bit Dell Optiplex with Pentium 4 (2.26GHz), 2.0 GB RAM, 1 TB SATA or 160 GB ATA hard disk.
The procedure used is quite easy and suitable for users of all abilities.
Important Installation Notes
Full Installation CD/DVDs. The Windows you are adding cannot be installed from Recovery or Repair CDs or DVDs provided by some OEMs. You need the full installation or setup version to install a Windows.
Shrinking a Windows 8, 7 or Vista drive. You should use Shrink in Windows' Disk Management to resize the Windows partition. You can read Shrink the Windows 8. 7 or Vista Partition for instructions on completing this task successfully. Use the free GParted Live CD to gain disk space only if you must - read the page Use GParted to Resize the Windows 8, 7 or Vista Partition to learn how.
SUMMARY of Procedure (Advanced Users)
That's it! The Windows boot loader menu will boot Windows 7 and the new Windows 7.
Details: Install second Windows 7 when Windows 7 is already installed
It's important to follow the instructions exactly as stated and you should have a properly working Windows.
Make your preparations
Make Unallocated space for the new Windows 7
The single 160 GB disk usually used in testing initially had: System Reserved (100 MB, Primary, Hidden, NTFS), Windows 7 (150 GB, Primary, NTFS). The Windows 7 drive was shrunk leaving about 40 GB Unallocated space at the end of the disk (to the right). After repartitioning it had: System Reserved (100 MB, Primary, Hidden, NTFS), Win7 (100 GB, Primary, NTFS), new Win7 (50 GB, Unallocated).
Next Install the second Windows 7
The new Windows 7 has been automatically added to the boot menu. Nice!
Congratulations! You have created a natural dual-boot of Windows 7 with a second Windows 7.
Repair Windows 7 Startup
You will not have any problem if you follow the instructions as stated above. However you might encounter some freak occurrence like a power failure during an installation. Windows 7 will boot again if you execute the following procedure.
If still stuck for a solution, boot again from the installation DVD, select Repair your computer, highlight Windows 7, get to a Command Prompt, use DIR command (DIR C: or DIR D: etc.) to identify drive letter allocations (sizes and Labels will help), and type in:
Please remember that you alone are responsible for the consequences of any changes you make to your computer hardware or software.
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