Let me find page 82 .... done!
(1) i think the digit people forgot u to tell that u should put ur WIndows XP CD in the CD Drive.
if u already 've a copy of xp setup in the harddisk replace the path with that.
(2) %SYSTEMROOT% is environment variable. just test by echoing it (in the command prompt :
echo %SYSTEMROOT%) so u dont need to replace anything.
(btw, if the first works, then no need of 2nd)