The first thing to do is to open the Disk Management utility in your computer. Disk Management can be opened by typing in “Create and format” in the search bar or it can be easily accessed by clicking “Computer ManagementèStorageèDisk Management” option in your control panel. All the partitions of your computer’s hard disk will be listed and all you need to do is to right click on the partition you want to resize. There are two options, either you can “shrink” or “extend” your partition space. Choose the option you prefer and enter the values in the column that appears thereafter. get more information and help for Windows 7 Partition hope this helps you.
I my system also same thing has happened c drive turned from primary to simple volume while shrinking. Now i want to install ubuntu 11 in my laptop keeping windows 7 as same. Can install Ubuntu without causing any harm to boot process of current Windows 7 after wards.