Ok, mystery now completely solved (and I was not wrong)

First, pressing "0" doesn't do ANYTHING.

But I did find out what the "EISA" Partition on this particular computer
(Toshiba A135-S4457) is and at least one way of getting into it.

On this computer, the partition contains the Vista recovery environment;
more or less the same one you can get into by booting from the Vista
DVD. See:

http://en.wikipedia.org/wiki/Windows...ry_Environment

This environment is on every Vista DVD; and if you didn't get a DVD
(e.g. Vista was pre-installed), Microsoft has made an .ISO file that
creates it on a blank (bootable) DVD available for downloading. See:

http://blogs.techrepublic.com.com/wi...windows/?p=622

The environment on the Toshiba has been enhanced with some Toshiba
extensions. It doesn't, however, fill the 1.46GB partition. There is a
"Restore" function to fully restore the main Vista partition .... but
the restore function is just a way of starting/accessing the recovery
DVD that Toshiba shipped with the laptop. As I speculated, 1.46GB in
the "EISA" partition is too small (WAY too small) to actually hold the
recovery files. That would take more like 4 to 6 GB.

As to the other part of the question, why it's called an "EISA"
partition: This was answered previously, but back in the 1980's when
Compaq and Zenith were doing their own thing to compete with IBM's
then-new Micro-channel (MCA) architecture, they came up with the EISA
architecture, and part of that was a provision for putting configuration
information in a hidden, protected partition on the hard drive. This
partition was given a "partition type" of 12H (18 decimal) and called an
EISA partition. Currently, it has become common (although not
universal) practice now to use this partition type (12H/18D) for
manufacturer specific diagnostic / restore partitons, but various disk
software (including Computer Management / Disk Management in MS OS')
calls a partition with this type an "EISA" partition, notwithstanding
that both Micro-channel and EISA died two decades ago [the market
ignored both of them and stayed with the ISA bus (augmented, for a time,
by the Vesa VL bus) until PCI came along in about 1995]. But partitions
with that partition type still get tagged as an EISA partition by
various disk software.

Finally, all of this is manufacturer (and, at least potentially, model)
specific. So none of it necessarily applies to any manufacturer other
than Toshiba or, for that matter, to other models of Toshiba laptops.
It is definitely clear that at least some manufacturers create such a
partition and make it much larger than the 1.46GB on this Toshiba
laptop, and then proceed to put a full recovery capability (including
either an installation source or an image source) into that [much
larger] "EISA" partition. Toshiba, however, still ships actual recovery
media with almost all of their laptops.


Barry Watzman wrote:
> Yes, I always admit that I am wrong once I realize that to be the case.
> The files installed on the laptop (and I don't think that anything
> major was added) totalled about 6GB; it's really tough to get 6GB's
> worth of files from a 1.46GB restore partition. In fact, I am not sure
> that you can restore either Vista Home Basic or Home Premium from a
> 1.46GB partition, it comes on a DVD and my recollection is that
> installation files take up between 3 and 4GB (the backup is of course
> image based, but there are about 6GB of files in the partition).
>
> On the other hand, it's very possible that it is a diagnostic partition.
>
>
> ggwillikers wrote:
>> Barry Watzman wrote:
>>> That is very interesting. [Hold down the zero key while booting; or
>>> press F8]
>>>
>>> I am still inclined to think that the answer is wrong, only because I
>>> still believe that a 1.46GB partition is too small to be a factory
>>> restore partition for Vista, but I will give it a try.
>>>
>>>
>> And if the poster is right, will you admit you're wrong????