Basic External Hard Drive Question

[verachion]

I am thinking about getting an USB external hard drive however I don't actually know much about them. Could you please answer the following questions for me:

1. When I plug this in to my computer will it automatically use the HD thats in the pc or the HD thats connected to the Pc?

2. Can I use both the internal HD and the External on one computer?

3. What happens if I boot the PC using the internal one and then plug the external one into the PC does that take over.

Would really appreciate some info on this please

[Sylvander]

"1. When I plug this in to my computer will it automatically use the HD thats in the pc or the HD thats connected to the Pc?"
Your PC will not attempt to boot from the external HDD, unless your BIOS supports booting from USB HDD's and you configure the BIOS to so boot.
On my PC [which doesn't support booting from USB drives, and therefore boots from the internal HDD], under normal circumstances the external HDD shows up within Windows only if the external HDD is switched on [therefore powered up].
If I switch on my external HDD before booting, it will be present once I get into Windows.
If I wait until Windows has booted before switching on, the drive is detected, and then appears in boot manager and Windows Explorer.
To switch it off, I must first click the drives' icon in the System Tray, wait until the drive close down notification appears, click ok in that box, then switch off the drives own physical power switch on the hardware.

"2. Can I use both the internal HD and the External on one computer?"
Yes.

"3. What happens if I boot the PC using the internal one and then plug the external one into the PC does that take over."
It just adds an extra HDD, and you can use both. On my system the OS is on the internal HDD and the external HDD is used only for data storage.
Are you thinking of installing an Operating System on each?
That would complicate matters. Not sure how to deal with that.

[Sylvander]

Here's the one I use http://www.vipower.com.tw/P_EE_VP-9258T.htm

I fitted my old 8 GB HDD into this and bought an 80 GB replacement to fit internally to a PCI to IDE RAID controller card.
I now use the internal IDE controllers only for the optical drives, one on each controller, so all the drives can now run concurrently because they each have their own dedicated controller.
I take it the one in the external enclosure also has its own controller inside the case.

Here's the ViPowER full range of external encosures http://www.vipower.com.tw/ExternalEnclosure.htm

Here's their home page http://www.vipower.com.tw/

The USB 2.0 cable [£25] is bought separately from the enclosure [£15].
You can have multiple low cost enclosures, each with a different type of drive fitted [HDD, optical], and have 1 [or more] cable[s] to use to connect.
The USB 2.0 cables have the USB circuitry built into the plug, and a small mini-CD driver disk is supplied [with the cable] with drivers for various OS's [beginning Win98SE = mine].

[verachion]

Thanks for the reply Sylvander. I should of explained in more detail, yes I am thinking of installing xp on an external hardrive. How would this work with plugging the external xp loaded HD in once the original internal HD has booted XP ?

[Sylvander]

I think I remember Paul Komski saying something about this.

See http://www.pcguide.com/vb/showthread.php?t=41998&highlight=Installing+OSes+external+drives

"How would this work with plugging the external xp loaded HD in once the original internal HD has booted XP ?"
In these circumstances I think the booted copy of windows would be able to view the files that make up the other Windows installation that has NOT been loaded. Booting this other Windows installation that's on the external USB connected HDD is another matter.

[Paul Komski]

I have both recently and in the past searched and searched and searched for someone who has successfully been able to install and boot WINDOWS from an external USB or Firewire accessed ATA HardDrive. Loads of people seem to say it must be possible if your BIOS has an option to select booting from a USB hard drive - yet no-one ever seems to have achieved it. I have myself booted to DOS on a USB flash drive and I have seen where both MAC OSes and Linux OSes have occasionally been installed onto external ATA Hard Drives. Windows, so far anyway, seems to be a non-starter even if your BIOS appears to support the option.

I dont know if its to do with PlugAndPlay or HDD enumeration or what but it is not straightforward. It is a widely sought after feature so maybe it will be made commonplace. If anyone has done this please let us know and let us know which mobo was used.

It may seem ODD that one can boot to USB CDs, Floppies and Zip drives with much greater ease than Windows on a Hard Drive - but there you are.

Of course, accessing the external from any OS and hardware that supports USB should not be a problem

[Sylvander]

One possible problem that I wonder about is the drive letter of the external HDD.
Isn't it possible for that to change [I'm using Win98SE] depending on the number of other dives or partitions?
And Windows depends so much on the addresses of files [as specified in the registry], and those would all change if the drive letter changed, and then nothing could be found. :(

Or would it be that if you installed to an active primary partition on the external HDD and then set the BIOS to boot from that, then that partition would be named c: and be unchanging, so long as the BIOS was set to boot from USB?
Then what would happen to the internal active primary partition?

[Paul Komski]

One possible problem that I wonder about is the drive letter of the external HDD.
The drive letter can change when it is accessed as an external data drive. All windows system partitions are given the C: drive letter and this should still theoretically be the case if you can boot from the external - though, for windows as I said, I have never yet seen this achieved. With DOS on an external USB drive it gets the "normal C" drive designation.

PS
The best way to minimise drive letters changing (particular relevant to DOS-based OSes) is to only have one primary partition on the boot volume and make all other partitions (on all drives) that you create - as logical partitions. If one is constantly juggling with partitions and changing drive letters it is possible to use things like the PM drive remapper to help change the paths back - but it is preferable to try to organise your use of partitions to avoid this.

[Sylvander]

Received and understood. :)

[verachion]

Thanks for the info on this.

So basically from what I understand I load XP using the internal HD in the Pc. Then I plug in the external hard drive, automatically it is recognised by XP.

I then go into it via my computer and the HD (DRIVE LETTER). Then pull out data from it and transfer between internal HD and External HD.

Can I run programmes / Applications from the external HD into the Internal HD for instance Say I load up Cyberlink DVD player on my external HD and would like to watch a dvd, do I just put the dvd in the dvd drive, and windows does the rest or would I have to install Cyberlink DVD player on the internal drive for the film to be recognised. Does windows fully intergrate the external drive in to itself or is it treated as a seperate entity?

I am looking to keep all my info on a HD and just have the very basics on the Home Pc you see. That way I can use my HD with any Pc to get my info off of.

[Sylvander]

"I am looking to keep all my info on a HD and just have the very basics on the Home Pc you see."
You could certainly keep [almost] all your data on the external HDD, except for data that is needed by a program for its proper functioning.
e.g
a. My Documents. [Use “TweakUI” to move their home]
b. E-mails for all identities. [use the email client to move their home]
c. Internet Explorer Favourites. [Use “TweakUI” to move their home]
d. Temporary Internet Files. [use the browser (Internet Explorer) to move them]
e. Re-home the Windows Address Book as shown here http://tinyurl.com/24q6l . Use the key “HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4\Wab FileName” to specify its new address. [Its normal home address [in Win98] is C:\WINDOWS\Application Data\Microsoft\Address Book\(the name you gave your PC).WAB]

I have all of these permanently moved onto my d: partition.
If I ever restore my c: partition to a previous state [to fix a software problem], then all of this data is untouched and up-to-the-second.
I could imagine you might move yours to an external HDD.
But for your various programs [Windows Explorer using "My Documents" | Outlook Express using the emails and address book | Internet Explorer using the Favourites & Temporary Internet Files] to work they would need to be able to find these files at the same address on a drive with the same letter.

There are other examples of programs that store their data files in a location recorded in the registry or some other configuration file.

It would be EASY to store on the external HDD all other data files not whose locations are not specified in the registry.

"So basically from what I understand I load XP using the internal HD in the Pc. Then I plug in the external hard drive, automatically it is recognised by XP."
YES.
I have my external HDD permanently connected as it happens [not necessary], and all I do is switch it on [the switch on the housing sends power through from the power unit that connects to it.
It is recognised by Windows and displayed.


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[Paul Komski]

The External Drive will almost certainly come with just one partition pre-installed on it and thus be given just one drive letter. It may be necessary to install software onto the main Operating System for the drive to be properly accessible - though this is more commonly the case with Windows9X and with drives over 137GB in size. It is possible to partition both internal and external hard drives so that you have more but smaller partitions - each partition being assigned its own drive letter.

Can I run programmes / Applications from the external HD into the Internal HD for instance Say I load up Cyberlink DVD player on my external HD and would like to watch a dvd, do I just put the dvd in the dvd drive, and windows does the rest or would I have to install Cyberlink DVD player on the internal drive for the film to be recognised.
Yes and No. Most programs are installed in such a way that the bulk of the Program Files are commonly installed inside the "C:\Program Files" folder. They can nearly always be installed somewhere else such as on another partition or another hard drive. During the installation the Registry is likely to be updated and other files may be installed in Application Data folders in a different location. Both of these two latter groups of files are generally kept on the C: drive. Thus if you install most programs from one computer's operating system they will commonly only work from that operating system but fail if accessed from another operating system on the same or another computer - UNLESS - they are reinstalled from the other OS or PC. This is not a constant and some programs will work from anywhere once they have been installed once. DVD player software will "tend to embed itself in the system" and would almost certainly need to be reinstalled from PC to PC.

What one can do if needing to run the same programs from different PCs (assuminmg your software allows you to do this) is to have the downloaded installers or even copies of whole installation CDs on the external drive and it should then be easy to reinstall them from PC to PC as needs be without redownloading or carrying a load of CDs around with you.

Data Files (documents, emails, favorites, music, photos, etc) are ideally suited to being stored on an external drive and thus be available in multiple locations - without the need to keep resynchronising, say a laptop and a desktop's, data files.

[verachion]

Thanks for all the advice, I am fully equipped with the knowledge you have given me. Thread closed for me many thanks again :)