Does Windows kill the "bootability" other secondary hard drives it
finds with the same OS on?

Just I had a old machine with Windows 95 OSR2 on, I then upgraded the
HD, installed the same copy of Windows on, and used the only bootable
hard drive as a secondary, to transfer stuff over, and as a backup for
important stuff. Then got a new machine. But now I've come to reuse my
old machine for the odd bit of internet access, I've put the original
HD back in, but I get the message "drive is not bootable" (or words to
that effect). I dont recall deleting any part of Windows on the old
HD, but it was all a while ago, so did Windows on the newer HD kill
it?

If so, do all versions of Windows do this? and do they just kill the
same version of Windows with the same serial number? or do they kill
the same version of Windows with any serial number? Or even kill any
version of windows with any serial number on a secondary HD?


Not sure if all versions do, but up to 98se all msdos systems I know of will
"kill" the ability to boot of a hard drive if you install it as a second
drive in any computer and then reinstall it as the "c" drive. The problem
is easy to cure. Install a bootable floppy and run the Fdisk program .
Be careful and go to the place where it asks you if you want to set Active
Partition. By doing this you will then be able to boot off the drive.

If the partition is not Active then all the data will still be on the drve,
you just can not boot off of it.