Hello hanukun and welcome to Seven Forums.
My one remaining brain cell doesn't always work so my apologies if this isn't what you were thinking of. I believe the Windows 7 System Repair Disk cannot be customized. Were you thinking of the custom Windows PE rescue disk? Macrium and EaseUS Todo both have a tutorial on how to create one: Create a Custom Windows PE Rescue Environment http://www.sevenforums.com/software/...g-program.html
I believe SIW2 (the Forum member who started the thread in the second link) also worked on some customized rescue/recovery disks but I can't find the link(s) right now.
Again, my apologies if this wasn't what you were thinking of. Perhaps some other Forum members will jump in to refresh my non-working brain cell.