where is function to change drive letter

Subject:
'Acronis Disc Director Suite 10', stand-alone version booting from original CD

The 'User’s guide' tells...
"
Chapter 4. Manual Partition Operations
> 4.2 Additional Partition Operations
>> 4.2.1 Changing partition letter
If you need to change a letter assigned to a partition by an operating system:
1. Select the hard disk and partition on it.
2. Select Disk -> Advanced -> Change Letter or a similar item in the Advanced sidebar list, or click Change the logical drive letter on the toolbar.
3. Select a new letter in the Change letter window.
"
But no such option to find in the running program. How to access/activate this function?

Intention:
Letter 'C' shall be assigned to 'Partition 2' while Partitions keep their number/order ) so that 'Windows XP' setup recognizes this and can be installed on 'Partition 2' 'C:'

P.S.:
How to change Partition number/order (without deleting Partitions). Is this possible with the 'Acronis Disk Editor'?

 

If you want the XP partition to be assigned C: when XP is installed, you need to setup the XP partition as a Primary partition and set it Active. You can't use DD or any other program to change this before Windows is installed.

DD can change the drive letter assignments when running in Windows (this option is not available when running TI from the CD). However, you can't change the Windows drive letter assignment without causing a lot of problems. It's best to get it right when it's installed. Disk Management can also be used in Windows to change the drive letter assignments.

Why do you want to change the partition number/order? What are you trying to accomplish?