repair installations and service pack versions for Windows XP (hom

I have a Windwos XP (home) installation (SP1) and a (original OEM) Windows XP
(home) recovery-CD. I also down loaded the repair disk sets for the repair
installation. For SP1 it consists of 6 disks.

Which Service Pack version will I need for a repair installation?

I also wonder why after using the disk set there is the request to insert
the Wiondows installation CD?

Thanks for your ideas.

Regards WalNi