Update
New versions of Ubuntu requires only one partition. The default installation process now creates a swap file in the main Ubuntu systems partition /
, rather than a separate swap partition described below.
Original Answer
Ubuntu need at least 2 partitions in formats that Windows does not understand and cannot create. You can shrink sda5 (D:) in Windows 7 and leave the empty space "Unallocated" and unformatted.
You should use Windows internal tools to defragment and then shrink or resize the D:. See http://technet.microsoft.com/en-us/magazine/gg309169.aspx . and http://www.techrepublic.com/blog/window-on-windows/quick-tip-shrink-a-hard-drive-volume-in-windows-7/3616 for detailed steps. Remember, do not create a new partition in the empty space. Leave it unallocated.
Ubuntu installation will then find the unallocated space and create sda6 (/
) and sda7 (Swap
) there during a "side by side" installation.
Ubuntu (and Linux in general) do not use C:, D: etc. to identify partitions. Partitions are mounted at various mount points
that can be a folder or a directory. An important mount point is root denoted by /
. This is the rough equivalent of C:\
where the OS will get installed. Other partitions are mounted to folders within /
. By default /home
is a folder in /
in Ubuntu. However, one can devote a separate partition to /home
by mounting the partition, say /dev/sda8
, to that folder. In that case all sub-folders of /home will be in the partition dedicated to it.
Note: the Swap partition has its own format and no mount point, as it is not accessed by the user directly.
See I have formatted a partition for Ubuntu. How do I install it on that partition? and Dual Boot Installation with Win7 - Install Ubuntu in New Partition.
Hore general instructions for installation is at: How do I install Ubuntu?.
Hope this helps