Don't feel bad about inexperience Rus. The main problem is for us to understand what your situation is when you don't have the knowledge to articulate it precisely, so please be patient with us, too.
Regarding your last post, we need to clarify the difference between recovery disks and the factory supplied System Restore disk. A recovery disk is something that you make yourself so you can get your computer running again in case of a system crash or corruption. If you haven't done this, you won't have any recovery disks.
The System Restore disk that the computer manufacturer provides with new computers will wipe your computer clean and restore it to the same condition it was in when it left the factory. So if you are running this process, of course it will ask you to keep inserting the CDs until the process is finished. I think my Acer had a 6 disk System Restore. If this is what you are doing, you will end up with Windows 7 on your computer when you are finished.
This is probably not what you wanted to do, unless you changed your mind and want to keep Windows 7. I'm guessing that you tried to follow the advice above about booting with your Windows 7 DVD so you can reformat your hard drive in preparation for installing Windows XP. The Catch 22 here is that it sounds like your computer manufacturer gave you a System Restore disk instead of a Windows 7 DVD.
But that's okay, because the same thing can be accomplished with the Windows XP installation CD. If you still want to switch to Windows XP, just boot the computer with your XP installation CD and follow the onscreen instructions to erase your hard drive and start with a fresh XP install.