Maybe you will have probably contemplated running multiple operating system on a single machine when there's a new operating system released. For example, when the Windows 7 released, most user's OS was XP or Vista, how to realize dual boot Windows 7/VISTA and XP?
To realize dual boot, we need two things-a Windows 7 installation disc and a fresh partition. We could get the disc through several ways. How about the fresh partition? The answer is repartitioning your existing hard drive then creates a fresh partition. Repartitioning your hard drive will vary depending on whether you're running XP or Vista—namely because Vista has a partition tool baked in, XP does not. To solve this problem we just need one solution-have the aid of some third-party partition manager such as the latest Windows Partition Magic.
Here we have an example under Windows XP; the existing hard drive is partitioned into three partitions. A system partition (drive C :) with two data partitions (D: and E :).
Step1. Download windows partition magic, install and launch it. Right-click drive E: in the main interface, then select "Resize"
Step2. In the pop-up window, drag right handle, leftwards to release the unallocated space (at least 16GB). Then click "OK"
Step3. Right-click the unallocated space on the main interface, select "Create Partition". In the pop-up window, specify the information of the new partition. Such as the drive letter, label (you'd better set up the label as Windows 7), file system, cluster size, volume size and the partition type (here we select "primary partition"). Then click "OK"
Step4. Click "Apply" on the tool bar. The operation will complete automatically.
Now that you've done all the heavy lifting, it's time for the easy part: Installing Windows 7 on your new partition.
Step1. Insert your Windows 7 disc, reboot your computer, then you will be guided into the installation wizard, just follow the wizard.
Step2. Select the target partition to contain your Windows 7 OS. (Be careful here. Choosing the wrong partition could mean wiping your other Windows installation altogether, so make sure you pick the new partition you just created. That's the reason why we set up partition label before).
After setting up all the information, just let the installer do its work. The operation will be completed automatically. Now boot your computer then you may find a new entry for Windows 7 on your boot screen.