I have a partition windows 7 400GB and 200GB, I want to install ubuntu 12.04 on the 200GB using a USB but am not sure how to identify 200GB when the installation process because it never shows a hard drive with that exact available space. I am not sure what to do, and I am not very familiar with ubuntu. Help please
Based on the information you gave:
Under Windows this is probably accessed as D: drive. Only proceed if you have not used it and there is nothing in the drive, else backup whatever data you have put there.
You can then proceed as Robert has said in his answer.
If you want to have a swap partition however, things are a little more complicated because the manufacturer (OEM) has already used up all four primary partitions that it is possible to have. The way around this is to delete /dev/sda4 completely and create an extended partition in its place. You can then have two logical partitions within this extended partition - One for Ubuntu / (root) and one for the swap file.
Two reasons why a swap partition is desirable:
I have the following suggestion which will get you installed in the easiest manner, with a swap file.
Since there will be blank unformatted space Ubiquity (the installer) will make an extended partition on which it will then make the / partition and a swap partition and install Ubuntu accordingly. If you want to do a more manual operation you can create the Extended partition, and then create the logical main partition and swap partition inside it if you wish, but the end result will really be the same.
You will want to use the Something Else option. On the choice on how you want to use your disks, pick
Find the 200 GB partition and click Edit after highliting it by clicking it. In the