not able to boot to Linux

[Yogi pn]

Hi,
    I have a dual boot machine with Windows 2003 and RHEL 4 configured on
it. I formatted a logical partition on windows 2003 and tried to reboot,
after that i'm not able to boot to neither windows nor RHEL, i get grub>
prompt after rebooting the machine!!!!! can you guys help me to troubleshoot
this problem!!!! Thanks in advance n have a gr88 weekend!

Regards,
Yogi