T43 recovery disks - what is the last one for?

[DoubleFace]

Hello. I restored my T43 to factory state with ISOs available from archive. There were 7 of them in total, but after installing the 6th one, the installation finished and rebooted to fully functioning Windows. Does anybody know what that last disk was for?

[Droider]

There are 7 iso available, 6 of them being data and 41A3952 is the RNR Product Recovery Disc which is 279,998kb. There is also 8th one which is 41X4112 Lenovo Supplemental Product Recover CD which includes extra software.