You need to change the entry in /etc/fstab to something like the following
Code:
/dev/hda1 /mnt/windows ntfs defaults,ro,umask=0000 0 0
Basically, whatever line has the vfat in it now, you just change to ntfs and then add the ro and umask options to make sure it is read only (write support from linux to NTFS is still dangerous, you might lose data).