Delete a partition when Dual-Boot is installed

Greetings!

On one of my 1 Tb disks, I installed at first Win7-32bit (Disk E on the picture). Some months later on the same disk I made a new partition and installed Win7-64bit (Disk C on the picture). When I boot I am offered to select which OS I want to use.

Now I would like to delete the Win7-32bit partition to use the place for something else (non OS).

Question: May I simply delete the partition where Win7-32 ("E" on the picture)? Won't the boot be affected?

Thank you!

Thank you, that is exactly what I needed! Another problem arrises: When I try to delete the partition (or to format it) where Win7-32 is (The bootmgr is located on another "Reserved" small partition) I get a message that "this partition is currently in use" or "A program or process on this partition is running".
So far I am unable to find which program it is, the task manager doesn't shown anything, regedit too...
I could force the format / deletion but....! Any suggestion?

Well, I could but it won't help! The thing is simple: Using an OS on a partition, the computer says that "a program or process" is currently in use, located on another partition with another OS that I want to delete :) Even after a reboot... SO I cannot format/delete the partition. How can I find which process is run from this partition?

Well... Screenshots are attached :)

I *am* booted in C and want to delete/format E.

The bootmgr seems to be in the "System reserved" on Disk2

On E I can see one folder "Bootwiz" with a date that can make me think it is used even if I boot on C...?

jsmo said:

Well, I could but it won't help!

Yes, it will help if you post a maximized screen print of Disk Management as suggested by ThrashZone using this tutorial to resize and show all info:
Disk Management - Post a Screen Capture Image

Then we can see where your bootloader is, what OS is booted, and more.
Your little snip in post #1 does not show any of this info.

In the "SAFE" disk - some personal data files only.

And so...