NTBACKUP restore problem

mcse_696

hi everybody
I backed up system state and c: partition on my xp machine, then I renamed hidden files ntldr,autoexec.bat,IO.sys, CONFIG.SYS.
first I tryed restore C: partition the restore failed, here some few lines from report
Restore Status
Operation: Restore

Backup of "C:", Restored to"C: "
Backup set #1 on media #1
Backup description: "Set created 12/7/2009 at 1:13 PM"

Restore started on 12/7/2009 at 2:58 PM.
Warning: File boot.ini was skipped
Warning: File MSDOS.SYS was skipped
Warning: File nagent_log.txt was skipped
Warning: File NTDETECT.COM was skipped
Warning: File ntldr was skipped
Warning: File NTUSER.DAT was skipped
Warning: File ntuser.dat.LOG was skipped
Warning: File ntuser.ini was skipped
Warning: File desktop.ini was skipped
then I restored from system state and completed successfully, the question why Full backup didn't work ???