Assignment of Partition Letters 1

[CondorMan]

I'd like opinions regarding a theoretical question that I raised during a hardware class.

I have a HD which I partition into 3 primary partitions (1, 2 and 3) and an extended partition which I subdivide into four logical partitions. I install Windows 98 onto partition 1, Windows 2000 onto partition 2 and Windows XP onto partition 3. Assume that I use FAT32 so everything's "visible".

I realise that the current active OS partition is always labelled "C:", but what about the other primary partitions? If I use Windows 98, are partitions 2 and 3 assigned letters in order D: and E:? What if I boot to Windows 2000 - are the assignments

Partition 1 - D:
Partition 2 - C:
Partition 3 - E:?

I assume that in this example, the four logical drives will always have the same assignments F:, G:, H: and I: with the CD-ROM being J: (is this correct?).

An extension to this is if I have a second HD which I partition in the same way and install three more Windows OS on the primary partitions. Would the letter assignments to the six primary partitions go in order:

C: - current OS
D: - HD1 first inactive partition
E: - HD1 second inactive partition
F: - HD2 first inactive partition
G: - HD2 second inactive partition
H: - HD2 third inactive partition

where first, second and third relate to the order in which the partitions were created on each hard drive? Finally, logic should say that master should have precidence over slave and primary IDE have precidence over secondary IDE.

I reiterate, this is a theoretical problem and my logic has determined the order listed above - I'd just like to know if my logic is flawed.

Thank you for your time.

 

[vacunita]

The theory goes the first primary partition regardless of OS will always be C:\

Whatever you install later in different partitions will take on subsequent letters.

So Partitions 1 2 3 would be in order C: D: and E:

Windows 2000 will find that it is infact installed in drive D: and can see drive C: as its boot drive.

WinXp will be Drive E; but agian Drive C: will be its boot drive.

If you keep on adding hard drives they will normally take precedence over the optical drives (CD-Roms, burners DVD's etc..) Those drives' letters will normally get pushed over.

However you can have optical drives be listed before other hard drives except for drive C:.

So you could have Partitions 1 and 2 Be C: and D: and then a CD-Rom be E, and partition 3 be F:.

In any case letter assignment can be manipulated as long as the drive/partition is not being actively used.
That is if your in Windows XP that resides on E: and boots from C:, you could change the drive letter from D: but not C: or E: as they are being used by the current OS.

----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[CondorMan]

That's brilliant vacunita, thank you. I was under the impression that the active partition (2 if I boot to Windows 2000 and 3 if I boot to Windows XP) would always be assigned C: but it appears that only partition 1 would ever be assigned C:.

A supplementary thought is regarding the boot.ini file. From the explanation that you have given, there would be only one boot.ini file, residing in the root directory on partition 1. If my theory had been correct (about the current OS/active partition always being C, there would have had to be several identical boot.ini files, one in each of partition 1, 2 and 3. It's a pity that I don't have a spare laptop and set of installation disks so I could have had a "play", rather than having to raise this here!

 

[ASG0856]

The important thing to remember is that the only boot.ini file that is read is the C:\drive boot.ini, regardless of which Partition the Operating System resides on. This is where you choice of Operating System to boot to comes from. So if you alter Drive Letter Assignment, then the boot.ini has to be changed to.

 

[CondorMan]

Thank you. It's starting to make sense now!

 

[vacunita]

Yes, there is only one Boot ini file and it resides on C: always, regardless of where your OS is installed.
Uusually the Boot ini that exists is the one made by the last operating system installed that has the capability of creating bootloaders such as Win2000 and WinXP.

Win98 however will overwrite any existing boot.ini and place its own, rendering any thing else unbootable.

That is why Win98 should always be installed first if it is to be used in a muliboot scenario.




----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[CondorMan]

Yes, I've seen comments on various sites about installing Windows 98 initially then others with the oldest first. I understand now that Windows 98 would overwrite boot.ini and make the others unbootable.

My original question related to installing several OS on separate partitions but I've seen a comment one one forum (I can't remember which) which implied that it's possible to install more than one OS on the same partition. I hadn't even thought about that because I thought that files (other than boot.ini with the same names) may be overwritten, so making one or more of the OS unusable. It strikes me that it's sensible to use separate partitions but, if I could install several OS on the same partition, are there any circumstances that I should do that rather than use separate partitions?

 

[CondorMan]

PS, I realise that if I want to use different filing systems (FAT32 for Windows 98 and NTFS for Windows 2K or XP), I must use separate partitions for different filing systems.

 

[vacunita]

You can potentially install several O.S.s in the same partition provided they can use the same filesystem


For Example Win98 andWinXP can both use Fat32 , if they were to be installed in the same partition,, they would obviiusly need to be in different folders, so If say Win98 was installed in C:\Windows, Windows XP would then need a different folder such as C:\WinXP or something similar to avoid overwriting system files inside the main Windows folder.

You would also have to consider the potential of system files in other folders conflicting with each other, such as the Program Files folder, as it would be the same folder for both O.Ses.

you would need to actually change folder locations for each OS so as to avoid conflicts. The Windows folder can be easily set from the installation, however other folders such as Program Files or the Temp Folder etc... would have to be modified from the registry after installation.








----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[CondorMan]

Thank you. Your explanation confirms my suspicion. I think it would be safer to install on separate partitions. That way, I could have access to Windows 98 and also the benefit of NTFS with the later OS. Whilst I'd be happy making the registry changes for the folders, it seems a lot of hassle for little (if any) benefit of having, say, Windows 2000 and WIndows XP installed in separate folders on the same partition.

 

[vacunita]

There really is no gain from installing 2 OSes in the same partition.

And the Risk of havig both O.Ses die when on the same partition is alot higher than if they are on individual partitions.

----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[CondorMan]

Yes thank you, I thought that would be the case.

I have a three further related questions about boot.ini entries:

Firstly, I understand that ARC addressing is used and, if the OS is Windows NT, 2000 or XP, the entry is something like:

multi(0)disk(0)rdisk(0)partition(1)\WINNT="Microsoft Windows 2000"

but if the OS is Windows 98, the entry is something like:

d:\="Windows 98"

Why isn't the Windows 98 entry similar to the Windows NT entry?

Secondly, the line "multi(0)disk(0)rdisk(0)partition(1)" takes numbers and rdisk(0) indicates the physical drive. Does this mean that Primary IDE Master is rdisk(0), Primary IDE Slave is rdisk(1), Secondary IDE Master is rdisk(2) and Secondary IDE Slave is rdisk(3)?

Finally, I understand that partition(1) is the first partition that was created on the relevant rdisk so, on a single HD system, I guess this would be C:, partition(2) would be D: etc.? If I was examining a system with several hard drives and several partitions (that I hadn't set up), is there any way to determine exactly which drive letter relates to which partition and on which hard drive? I suspect that I could take the drives out, reset master/slave etc. and reinstall then make notes as I interrogated the drives to see what files are where, but is there an easier way?

 

[vacunita]

For the boot.ini and ARC naming conventions have a read here:

http://support.microsoft.com/kb/102873

Assuming you have no access to Windows but you can boot from a floppy and run NTFS capable fdisk from it, it will tell you what drives have what partitions.

If on the other hand you do have access to and O.S. each Os has different tools to provide that information. WinXp has the Disk Management console, win98 has the prodigal Fdisk utility from the command line etc..

you could even attempt to download third party apps like Partition Magic and it would also tell you.

As a rule i always keep a bootable floppy or CD with the current command line version of Part Magic for just such purposes.




----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[CondorMan]

Thank you - it looks like I have a bit of homework to do!

 

[BobbR]

WinXP does not require presence of a C: drive in order to boot up. My OS is installed on G:. C: drive is reserved for USB thumbdrive. Win Explorer shows first drive as D: unless the thumbdrive is plugged in, where it will then display the C: drive.

 

[vacunita]

That's a very specific circumstance and a highly unorthodox setup, and it probably was due to how windows XP was installed. on a pre existing Drive G. Without a C: drive being present at the time.

However in the overwhelming majority of cases, when you install an OS in another drive other than C: and C: is present, the boot files including the boot ini will be located there.

If however you install Windows in another drive without a Drive C: present then the boot ini files will be located in whichever drive you installed Windows.







----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[firewolfrl]

To add to the discussion... some older compaqs assigned the primary as different then C:

if you have a zip drive this will change the installation drive.

if there is a boot manager that may change the install too

LOL...I have had at one point or another multiple cloned xp on one drive to test software. I use an old program called XOSL (bootmanager)

http://www.ranish.com/part/xosl.htm

it has an option to reverse secondary and primary drive positions and fool the OS. also to note you can install windows on an extended partiton with a little bit of work

gotta hell of a wind storm (60-80mph)brewing outside so I gotta go for now