vaio recovery partition is missing

hello i have a sony vaio with preinstalled win 7.i have upgarde s everal times to win 8 and also several times i restore , with vaio recovery soft or with F10 , to afctory s ettings.i try to make a clean isnatllation of win 8 .i do it three times.the last time when i try to restore to factory s ettings the F10 don't work.in my disk manager i see the big recovery partition (14 GB) but can't restore anymore in factory settings.neither F10 or vaio recovery soft work.i think like another post i see, that the link to vaio recovery partition is missing!!can i do anything for that?i do not have and installation disk

Yes it will be erased if you have installed Windows 8. You are going to have to contact Sony to see if they even still have the Windows 7 discs avail. Most likely the answer will be no and you are stuck with either buying an OEM disc & key from newegg.com or stuck with Windows 8.

right click start flag > command prompt(admin)
Type> diskpart

type> select disk 0
type> list partition
type> list volume
(post a pic)

you will see a lot of volumes without drive letters assigned..
Now find the 10-20GB volume #
type> select volume # (# being the volume number without a drive letter)
type> assign letter=r
you can now Browse thru R and find Install.wim or Install.swm(s) - those are your Factory recovery Images..

type> exit (to exit diskpart)
type> reagentc /disable

type> Reagentc /Setosimage /Path R:\RecoveryImage /Target C:\Windows /Index 1
assuming the install* file(s) are on "R" and in a folder called "RecoveryImage"
Note: Change "drive letter" and "folder name" to suit your system setup

type> reagentc /enable
reboot PC

in step with assign letter=r appears the next message :

i retry but in step with assign letter=r appears the message the letter r is not free

thanks kyhi but nothing change,in volume with 14GB (former vaio recovery) appears only a temp file with some texts!!thanks anyway

also the command :Reagentc /Setosimage /Path R:\RecoveryImage /Target C:\Windows /Index 1 is with index 1 in the end or not?