Partitions Manager

Hello there,
I'm trying to extend my System Disc (C), but Extend function is inactive. I only can Shrink my C:, and Delete, Shrink my D:.
Any solutions?
Sorry for my bad eglish. Soon, I will speak better, hope so.

You have to shrink D(Data) partition before extending C partition.

Thanks, but if I Shrink my D, Will I lose my data, and if i Will extend my C too??

You can shrink C partition without deleting any data(see attachment, I have shrunk C and I got unallocated partition right to C). Here,you can only extend C partition but not D.
Now you have to transfer all your data from D to C partition, then delete the D partition and you can extend C partition to a desired amount and you can create D partition and put your files back in D(those you transfered to C).
I have to mention that you can not shrink D and extend C as the unallocated partition will be right to D partition(sorry for my initial post).
You can get more info from this tutorial as well:http://www.vistax64.com/tutorials/95418-disk-management-delete-extend.html