Dual boot with same partition

Hewlett-packard / Z400
August 7, 2009 at 04:33:37
Specs: Windows XP
I have a application that I want to test on two different operation systems. I have av PC with two hard drives, one with Win Xp and one with Win7. It´s no problem to choose which hard drive to boot from. But the problem is that my application must run under the partition C:. That means that booth hard drives must have the same partition (C:). Is it possible to solve this with some boot manager or something like that? Or is it maybe better to control this in the BIOS?

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#1
August 7, 2009 at 05:36:15
First off, are you sure you can't install the program on a different partition? Most programs can be installed where you want them. You may need to use and advanced or custom install to get any options on the path.

Most modern BIOSes have many boot options. With all the controllers on newer motherboards boot selection options are offered.

You can install an OS on each drive and have them both boot as the C drive.

Install each OS while the drive you are installing to is the ONLY hard drive connected at the time. After both OSes are installed you can reconnect both.

In the BIOS boot selection you select which hard drive to be the hard drive to boot to. That drive will be the default drive.

On the system I am on currently I have an option to select what to boot from at start up by hitting Esc.

Doing that gives me a menu to choose from. One of the choices is simply hard drive with an askerisk behind it.

Selecting hard drive gives me a submenu with all available bootable hard drives. Choose the one you want and hit enter to boot to that drive.

When you do enter Windows the C drive letter will be assigned to the running OS.

If your BIOS doesn't have those options then a boot manager would be the alternative.

If you already have both OSes installed then using the BIOS choices may result in boot failure on one or both OSes due to the boot.ini.

You would need to modify it. This assumes you installed both OSes with both drives connected.


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#2
August 7, 2009 at 06:43:59
It worked fine when I disconnected one hard drive and installed the second OS. Then I just have to "remove" the hard drive that I don´t want to use in BIOS.

It was much easier than I had imagined. Thanks for the help!


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#3
August 7, 2009 at 07:27:42
"First off, are you sure you can't install the program on a different partition? Most programs can be installed where you want them. You may need to use and advanced or custom install to get any options on the path."

Very good point. If you can install it to another partition, the vast majority of it is installed on that other partition, only a little is installed on C to point to that.
........

See response 2 in this recent topic for more info about how XP determines which drive letter it sees itself as using:
http://www.computing.net/answers/ha...

Unlike the case for XP and 2000, Vista, and, probably, Windows 7, (I have discovered that it) automatically always sees the partition it is installed on as C, no matter whether there are already other operating systems or other hard drive partitions that have already been installed on the computer that have drive letters assigned to them when Vista's (or Windows 7's) Setup is run.

Your present method of "removing" the hard drive that you don´t want to use in BIOS, and booting only the operating system on that, will work fine.

However, if you ever set up dual booting XP and Windows 7, you will probably have the same problem as when you dual boot XP and Vista - all the Vista (or Windows 7) System Restore restore points are lost when you boot XP, every time you boot XP.
..................

Some notes I made. The same probably applies to Windows 7.....

1. It's relatively easy to dual boot XP and Vista, even if they're on different hard drives and were loaded on those drives by themselves, and there are free programs available that make tweaking that easy. However, by default whenever you boot XP, ALL the accumulated System Restore restore points are lost in Vista, every time you boot XP (or 2000). That was a bonehead thing for Microsoft to not fix before they released Vista.
If you don't want to lose the Vista System Restore restore points every time you boot XP (or 2000)............
There is no Microsoft fix. There are Microsoft suggested workarounds, but some are only available if you have a Vista Ultimate or a Vista Business version (most people are using Vista Home Basic or Vista Home Premium because they're cheaper - brand name systems usually have Home Basic or Home Premium on them), and there is Microsoft suggested registry tweak you can do in Vista, especially useful if you don't have the Ultimate or Business version of Vista, but not every program you can load in Vista is compatible with that tweak, and in that case you have to undo the registry tweak at least temporarily, and then you lose the Vista restore points anyway.

The best solution, if you don't have the Ultimate or Business version of Vista, is to use a third party multi-boot boot manager program that can HIDE the Vista partition from the XP installation while booting XP, then the Vista restore points are NOT deleted.
I tried Partition Magic 8.0's Boot Magic program - it works, but it does not enable a mouse to select the operating system with (that was required for the disabled person that owns the computer) . I searched and found several boot manager programs with mouse support, that support booting Vista - some free - most will work with a USB mouse if Legacy USB or similar is enabled in the mboards's bios Setup. The ones you pay for are about $25 and up.I found a site that says many of these don't support the Hibernate feature for mboards in Vista properly, but otherwise they work fine. (Since I did not continue with trying Boot Magic, I don't know if you can configure it to HIDE the Vista partition from XP while booting XP, or whether it supports the Hibernate feature for mboards in Vista properly.) I tried one free Linux based one - could not get it to work - not enough help info came with it or available online.
I tried BootIt! New Generation - it works fine and it DOES support the Hibernate feature for mboards in Vista properly, but it's $35 US after 30 days. It's install program is only 8xx kb and easily fits on a boot floppy, or you can make a bootable CD - it's nice to know someone is still making programs that are not bloatware. It includes a simple partition manipulation program that you can create, resize, move, delete, copy, merge, etc. partitions with. It has lots of help in the program and online, but you do have to find out how to do some stuff manually (e.g. enable it to HIDE the Vista partition from the XP installation while booting XP), so it's not suitable for someone who's clueless.

(If you need more info about using BootIt! NG, PM me).

2. Vista doesn't make NTFS partitions 100% the same way as XP and previous OSs do. It starts the first one a bit farther into the hard drive (rather than at sector 64) , and it can leave unallocated sectors between multiple partitions on a drive. Part of the reason for that is to accommodate new hard drives that will be using larger than the 512 byte sectors they've been using up till now, in the future I assume.
It also has non-standard data in a certain standard feature associated with the partition (the name of that I don't recall, but I could dig that up).
This results in - to fix the non-standard data -
- Partition Magic and some other older partition manipulation programs that are not Vista ready or similar don't recognize the Vista NTFS partitions as being valid.
Partition Magic sees the partition type as ??? and as completely filled, whether it is or not.
If the first NTFS partition on a hard drive was made by Vista, Partition Magic won't even load and generates an error code (in my case it was on the second partition).
You can cure that by running chkdsk /r from XP, by booting with the XP CD and using the Recovery Console option, and checking the partition Vista has been installed on, then Partition Magic etc. see the partition normally. However, that can take several hours - running chkdsk /r takes a lot longer than running chkdsk /f - you can't run the latter in the Recovery Console.
OR if you're starting from scratch you can make all the partitions with something other than Vista, instead of using Vista to do that - in which case such programs will recognize the partitions normally. Vista recognizes partitions made with older programs and OSs (Win 98 and up) fine.
- (NOTE that this may only apply if you use a third party multi-boot boot manager program that can HIDE the Vista partition from the XP installation while booting XP) - even after you have run chkdsk /r from XP, Vista can see and access the XP NTFS partition, but XP can't show or access the Vista partition (at least, the one Vista's Windows was installed on) in My Computer or Windows Explorer - it does show up in XP in Disk Management but as an unknown partition type. If you want to be able to exchange files both ways between XP and Vista Windows partitions, you need to make at least one other partition that doesn't have Windows Vista on it that both OSs can see, and place files you want to share on that.
- Vista can shrink (resize it smaller) an existing partition, so you can use the unallocated space then made available to make more than one partition on a drive without losing the data on the one(s) that already have data, but if you alter the partition with something other than Vista or a 100% Vista compatible program, Vista may no longer work at all and has to be re-loaded from scratch. It is also dicey to copy a Vista made partition - it can be done but you have to look up how to do it properly online.


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Related Solutions

#4
August 7, 2009 at 13:47:00
Dunno about all that.

C drive is relative to the booted OS. You don't have to do anything ODD.

Just install the app into each OS as you wish.


Pretty sure you can still run both OS's from the same partition but I have not tried it. You would still need to install it to each OS or fix up at least one registry.

"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, Make an autorun.inf folder on all usb drives.


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#5
August 7, 2009 at 13:51:43
jefro

The OP has TWO hard drives with an OS on each one. They simply want whichever OS they boot up to be assigned the drive letter C. The OP is referring to the drive letter assignment as the partition.


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#6
August 7, 2009 at 14:36:23
"Pretty sure you can still run both OS's from the same partition ......"

Each operating system can see itself as being installed on C, but they aren't the same partition - in that case if you are multibooting and they can see each other's Windows partition, the one you're booting from will be C, the other something else - and you can't run two Windows operating systems from one partition.


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