delete 1 partition's OS and save other OS

How can I delete a partition with an OS on it? i have a laptop with 2 150 GB partitions. each has Win 7 ultimate on it. I tried to do a clean install after \I deleted win 8 and win 7 but now I have 2 win 7 ultimate on it. I want to deleted one and jut have 2 partitions , one C OS and the other D for whatever I want. I have easeus partition manager and I have acronis 12 and Active @ . I could have taken it to a shop for the price of the software!! But I want to learn myself. Any help would be greatly appreciated. I would like to delete D partitions OS and just have empty space for ???
best regards
Razz

hope this is what you want:

when I try , i get a pop up saying : Win unable to complete the format

It won't format and shouldn't because the System boot files which are booting C are on D now and need to be moved first to C. We can tell this by the System flag.

To do this power down to unplug the D drive and swap its cable to C HD so that it is in Disk0 position which is safest.

Then boot into Win7 DVD System Recovery Options or System Repair Disk to run Startup Repair - Run up to 3 Separate Times which will write the System boot files to C and make other adjustments needed like writing the repair console to F8 boot tools menu.

Once Win7 boots on its own and is marked System Active you can plug back in the other HD making sure C remains first HD to boot in BIOS. I would move the data off the other HD to wipe it with Diskpart Clean Command and then repartition in Disk mgmt.

this is a laptop with a 300 gb hard drive partitioned into 2 150' and then subsequently divided again. I would not know what to unplug at all.

ok I did that

sorry did not scroll down to exit
will try again

here is a snap