Well. here grub is fine, boot.ini is fine.. problem is that your few windows files are missing .
And this question has been lots of times answered in forum.. ok check here
Linux & windows XP booting problemand hint is that boot from windows installation cd then go to recovery mode then copy hal.dll from i386 directory of cd to to windows directory etc.. also you can first search for MS site to recover win XP booting then you have to install grub.
To install grub.
boot from Linux installation cd ..
go to linux rescue mode by typing
linux rescue
just after booting when it shows first slash screen with command prompt.
then follow instructions and mount your system under /mnt/sysimage
then run following command
grub-install /dev/hda
Hope u r cleared.