Actually, it's pretty simple. Boot a DOS disk. Run 'fdisk /mbr'.

Mind: my preference would be booting FreeDOS, not some borken Microsoft crap. But all the same.

My experience is that fixing Linux GRUB issues is also pretty straightforward. Helps to understand chroots and stuff, but still: boot a bootable distro (Ubuntu or Knoppix on a USB stick rawks), chroot into your installed root FS, mount /boot if necessary, and run 'grub-install' or 'update-grub'.

Mostly just works.

I know, I just happen to be using Ubuntu. However, 99% of users will blame Ubuntu. (I think the issue is already fixed in newer versions of lvm2 (or grub2, I can't remember which they patched.))

Am I missing something with Windows? Can it detect non-Windows partitions? How can I fix it?