how to repair grub
 

i have installed first xp after that liux . but now i want to format xp . but xp is not formatting now so please help.

I'm not understanding the question.... Is grub damaged or are you having trouble formatting your windows partition?

Welcome to LQ!!

You will need to give us more information.

First, are Windows and Linux both working?

Second, what do you mean by "format XP"? Do you want to re-format the XP partition so that XP is removed?

I'm sure (but I could be wrong) you would be able to remove the Windows XP partition through gparted

if that's the question, then you can remove a partition with **ANY** partitioning tool......