I have a separate drive for windows and linux. Grub was struggling to boot windows i would get
"file system type uknown, parition type 0x7"
I got this error using a grub config of
makeactive chainloader +1
I also tried
This setup would just hang and eventually prompt for a Ctrl Alt Del
To keep windows happy this setup seems to work fine for me in grub.conf. hd0,0 is my linux drive and hd1,0 is the windows drive.
title The Windoes root (hd1,0) map (hd1) (hd0) (hd0) (hd1) makeactive chainloader +1