Hmmm - I go to bed and the thread erupts.
The referenced link whilst extremely M$osft centric, and in some places wrong, is non-the-less very good.

It explains (included links) why there is a (Windows) "system" partition at hda1, and a "boot" partition at hda5. Yes, it sounds fscked up, but he is correct to use those terms. Also explains why hda5 will be un-bootable directly - even using "fixboot" probably won't resolve this.

Edit: Should have mentioned that M$soft have allowed the "boot" partition (where the system code lives) to be a logical for years. If using their boot-loader, they require the "system" partition (where the boot sequence code lives) be a primary partition on the primary (BIOS) boot disk.
(Pays to study this early in the day with a cup of coffee handy, not late at night with a beer in hand).

As opposed to "late at night with a beer in hand" ... when Microsoft's multi-boot strategy was developed!!!

Nice going guys, you brought a tear to my eyes!!!! This one may deserve stickification.