[ltp] [T42] can't reboot on windows after installing gentoo

[sebastiengrillot]

Hello every bodies.
First of all,  sorry for my english i'm a french guy who is in strungle with shakespear 's language !
Well i have an issue after installing a gentoo. I can't reboot on windows. I have installed grub and when i select this item grub saids "error 12". I read a lot of threads and now i know there is an issue with kernel 2.6 and window about the hard disk (one "see" directly the HD and the other trought the BIOS, isn't it ?) When i did fdisk -l i have a lot of Partition does not end on cylinder boundary.
I ride this BIOS LBA Setting. If your BIOS contains a disk geometry option, change it from Auto to LBA. This options is not available on the laptop BIOS's I have seen.
What can i will do ?
Can you help me please?

Regards

Sebastien