Dual CentOS, Windows 7 boot. Had to delete CentOS partition and no grub menu.
3 partitions (in order): Windows 7, CentOS and shared data partition.
I need to increase the size of the Windows 7 partition (c:\windows\winsxs seems to be something not easily remedied).
GParted didn't work in moving things around (bad sector) so I wiped out its partition (# 2 out of 3) and I was able to increase the size of the Windows 7 partition (I can reinstall CentOS easily and not much work lost).
Except ... no more grub menu (unsurprising). This incantation does allow me to boot into Windows 7.
grub> rootnoverify (hd0,0)
grub> chainloader +1
Is there any way of rebuilding the grub menu short of reinstalling CentOS (5.5)?