Hi,
Could you provide more information about your setup, please? What does your partition layout look like? What filesystems are you using for your operating systems? What version of Windows do you have? Some computers have a hidden 'recovery' partition stored on the hard drive in the case that the primary partition fails to boot.
Finally, you can try manually booting Windows by using the following commands at the GRUB promp (hit 'C' to get to the command prompt as instructed by the GRUB menu)t:
Code:
rootnoverify(hd0,0)
makeactive
chainloader +1
boot
In the above example,
hd0 refers to the first hard drive on your system. If you have multiple hard drives,
hd1 would refer to the second hard drive, etc. Likewise with the partitions. The second
0 refers to the partiton number.
Hope this helps.