usb booting

Hi, i followed the guide to set my usb drive to boot windows 7 ,below.
All goes well until select partition 3 in my case.
I get an error saying no partition selected?Any one an idea as to why it sees the partition in List Disk but not when i get to the part select partition 3?





DISKPART and hit enter.
LIST DISK and hit enter.
Once you enter the LIST DISK command, it will show the disk number of your USB drive. In the below image my USB drive disk no is Disk 1.

4. In this step you need to enter all the below commands one by one and hit enter. As these commands are self explanatory, you can easily guess what these commands do.
SELECT DISK 1 (Replace DISK 1 with your disk number)
CLEAN
CREATE PARTITION PRIMARY
SELECT PARTITION 1
ACTIVE
FORMAT FS=NTFS
(Format process may take few seconds)
ASSIGN
EXIT

No,my usb drive is partition3,so i would enter 3 as 1 is another drive.

I tried as you suggested and list volume says usb drive unusable and it wont format>

Yes as i said thats what i did!1


Hi, i followed the guide to set my usb drive to boot windows 7 ,below.
All goes well until select partition 3 in my case.

Ok.i think i did that but wrongly said partition3.I will try again and see what happens.

I have been doing it correctly but get to select partition 3,the get this error