Windows 8 is the codename for the upcoming version of Microsoft Windows that follows Windows 7. It features a new Metro-style interface that is designed for touchscreen, mouse, keyboard, and pen input. It also adds support for the ARM processor architecture in addition to the previously supported x86 microprocessors from Intel and AMD. Its server counterpart is codenamed Windows Server 8. If you like to try Windows 8 but don't want to give up Windows 7. Here's how to dual boot Windows 8 with your current Windows 7 installation so you can run them both side by side. All you need to do is create a new partition for Windows 8, install it on that partition, and then edit your new boot menu so Windows 7 stays the default OS.
Step 1: Create a partition for Windows 8 installation under Windows 7
First Option: Use Windows built-in disk manager
As you can see in my disk management, I have a 160GB hard disk that is configured with a 64GB partition on which Windows 7 is installed and other two data partitions. What I need to do now is to make a new partition for Windows 8 installation.
Open the Start Menu and right click on the "Computer" option. Click "Manage", and in the window that appears, click on "Disk Management" in the left sidebar.
Find the system hard disk in the graphical list that appears in the bottom pane. Right-click on the partition F and then click "Shrink Volume". Shrink it down so you have at least 20GB of space left on the end of the drive, and click OK. Then, click on the "Unallocated" block of that drive that appears and click "New Simple Volume". Click Next on the next few windows until you get to the "Format Partition" window. Here, give it a volume label you'll recognize (like "Windows 8") and click Next. It should format the drive for you. Now you're all set to install Windows 8.
Second Option: Use EaseUS Partition Master Home Edition
You can also use partition freeware - EaseUS Partition Master Home Edition to resize partition and create new partition. It enjoys great reputation for optimizing disk space and CNET also recommends Windows users to use it for dual boot windows 7 and Windows 8.
Step 2: Install Windows 8
After creating the new partition, it's time for the easy part: Installing Windows 8 on the new partition. Insert your Windows 8 disk installation CD and reboot your computer (you'll need to have enabled booting from your DVD drive in your system BIOS).
Windows 8 Developer Preview Download
Windows 8 Consumer Preview Download
Windows starts to install automatically. When you're choosing installation type, be sure to select Custom (advanced).
Be careful here. Choosing the wrong partition could mean wiping your other Windows installation altogether, so make sure you pick the new partition created for Windows 8 installation in the first step. Choose it to continue.
When you're done, your computer should reboot into Windows 8. It'll probably reboot one more time after it does, then you'll be greeted with the Windows 8 Start screen. If you choose to enter a Windows Live ID here, make sure you have access to your email and can confirm your computer - otherwise it might not let you boot into it.
Step 3: Make Windows 7 the default (Optional)
When you first boot up into Windows 8 that you're presented with a new graphical boot menu that'll let you choose between your Windows 7 and Windows 8 installations. Windows 8 will be the default, meaning if you don't manually choose Windows 7 from the menu, your computer will boot into Windows 8 after three seconds of inactivity. If you don't want to make Windows 8 the default quite yet, so here's how to make Windows 7 the default.
On the boot menu, click on the button at the bottom that says "Change Defaults or Choose Other Options", and hit "Choose the Default Operating System". From there, you can pick Windows 7 from the menu. From now on, your computer will boot into Windows 7 by default.
Now you have dual booted Windows 7 and Windows 8 sucessfully!