Linux corrupted something

I installed Mandriva linux free 2006 on an external HD, when i booted it up before it got to the bootloader menu it displayed, L 08 08 08 08 08 08 08 08 08 ... about 100 times and the system gets stuck. I tried reinstalling linux, then windows but nothing seems to work. I installed linux by itself on the main HD and it loaded fine but when i recovered windows it displayed, L 99 99 99 99 99 ... about 100 times and got stuck again. Does anyone know what could be wrong?

It mangled your master boot record for some reason.

You can clean that easily with a MS-DOS boot floppy, you type 'fdisk /mbr' at the prompt. I can't remember if you need to reinstall Windows after that, but I think not, I suppose it should reboot in the Windows already on the drive.

When installing Linux, I think you should put the boot sector on its root partition (i.e. /dev/hda1) instead of putting it on the MBR (i.e. /dev/hda). Then at some point during install process you can create a Linux boot floppy, you need this floppy because the MBR don't know anymore that Linux exists on the drive.

If you want Linux and Windows dual boot menu. You type 'dd if=/dev/hda1 of=/linux.bin bs=512 count=1' from Linux, then you copy the file linux.bin on C:\ partition under Windows and you append the line C:\linux.bin="Linux" into the C:\boot.ini file. This way you can choose which one to load at boot time.