its simple , first install Windows on Primary Partition C Drive and then use any partitioning software to delete any of the partition in which you want to install Ubuntu or use Windows Disk Management to delete that partition .Preferably choose the last partition of your disk having at least 20gigs.

Create Bootable USB Stick y using Universal Universal Installer , as explained here or create a bootable Dvd as Shown here.

Then restart your system and enter into Bios and change the boot Priorities to either USB or Dvd, depending on what you are using to install it.

After Saving changes restart your pc and connect USB then Ubuntu Installation Interface will be prompted , in that choose INSTALL UBUNTU , provide all the details , When it ask for where to install choose Something Else , here you have to be very careful , do exactly what I am about to say -

Look at the partion , there will be one named as FREE SPACE click on that then click on + to split it into usable partition , then change the size of the partition by scroll down option or enter it manually ,the size should exactly same as the Physicall ram or Double of it and in the format option choose SWAP AREA let it be logical and check at the end of SPACE. till now we are done with creating swap partion.

Next click on + again and let the size as it is then check begining of the space and choose partion EXT4 and in the mount Option choose / that is for root partition means everything will be installed in it, and let this to be LOGICAL.

Click next and Install it .

Remember both the partitions are LOGICAL , swap is at the end of space and root at the beginning ,in swap just select format as SWAP AREA with no mount option and for root Partition choose the partition EXT4 with mount point / .

Hope i have explained exactly what you want.