how to safely format Windows 7 on C: and keep Windows 7 on D:?

[DrGhobar]

safely formatting Windows 7 on C:; causing no problem Windows 7 on D:?

Do you know how to safely do the following task?

formatting Windows 7 on partition C: to completely empty it, without making boot problem for Windows 7 on D:.

 

[AddRAM]

You need to post a shot of Disk Management before we do anything.

 

[DrGhobar]

You need to post a shot of Disk Management before we do anything.

Now that I am posting here, many things have changed in that computer. That is, the partitions and other things have changed.