There is a hidden partition created by default in Windows 7. This can be very frustrating, especially for IT administrators who are working with capturing and deploying images with Sysprep and ImageX. The boot files needed for Windows 7 to boot correctly are stored on this 2nd hidden partition. This will show you how to install Windows 7 on one partition.
How to install Windows 7 on one partition
First, there is no way to simply delete this hidden 100MB partition in Windows 7; you simply have to reformat. So the first step is to backup your data and boot to the Windows 7 Install CD. (To boot to CD, restart your computer and normally it will be either DEL, F12, or ESC key to select CD-ROM drive, and boot to it)
Once you are up to the Windows 7 screen, you will need to select “Repair Your Computer” option.
Next you will need to select “Command Prompt”.
In Command Prompt we are going to reformat your hard drive in a certain way so the 2nd partition doesn’t automatically get created when you install Windows 7. Here are the comands:
List Disk (You might have more than one hard drive)
Select Disk 0 (By default your main boot drive will be disk 0, check it)
Create Partition Primary
Select Partition 1
Format FS=NTFS Quick
Then simply walk through installing Windows 7 as you would normally. This time the setup will not create the 100MB hidden reserved partition.