Multi-boot / Boot Manager problem with Windows 7, Windows XP, and WIndows 2000

Apologies in advance for the long post ... but there are many pertinent details...

I'm having two problems (which I suppose are inter-related) on a PC which I set up to be multi-bootable with Windows 7, XP, and 2000:

1. When I boot into Windows 7, the Disk Manager for some reason is not assigning a drive letter to the Windows 2000 partition. The partition does not "show up" at all under Windows Explorer. And in Disk Manager the partition is visible but under Volume, where I should see a drive letter, it is just a blank space.

2. When I try to boot onto the Windows 2000 partition I get the BSOD, with a Stop code of 0X0000007B and message saying INACCESSIBLE_BOOT_DEVICE

This is a brand new PC I just built. And although I am not normally one to take up a new Microsoft operating system until a year or more after its release, due to the new 64bit hardware I made an exception to my self-imposed rule, and bought Windows 7. So ... here is what I did (in order):

1. Assembled the PC components / hardware, which includes a single WD 2Tb SATA HDD.

2. Installed Windows 2000 Pro SP4 from CD, into a 20GB partition formatted NTFS. Then booted a couple times to make sure it started up (which it did, just fine). Under Device Manager I saw many unknown hardware components (as expected), which I didn't worry about (because I just wanted the Windows 2000 partition there in case I want/need to actually use it at a later date). I left the drive letter assigned to the default C:\, and left D:\ as the DVD drive

3. Installed Windows XP Pro SP2 disk and formatted a second 20 GB NTFS partition, into which I installed Windows XP. Left the default drive letter assignment as E:. This installation also had some unknown hardware, for which I again didn't bother updating drivers because I'm only putting the partition in "in case I need it later." I booted back and forth between Windows XP and Windows 2000 a couple of times, to make sure both worked ... and they did.

4. Then I inserted the Windows 7 64bit DVD, formatted another NTFS partition (50 GB this time), and installed Windows 7 into it. The Motherboard is MSI P55-GD65 and I installed drivers etc. from the CD that came with the motherboard. Things seemed to be working fine, with the dual-boot menu appearing and Windows 7 booting up and running ok.

Then I noticed a strange thing (maybe not a "problem" ... just strange) happening when I run Windows 7 -- I guess since the Windows 2000 partition is not being recognized there is no C drive letter assigned ... and so when Windows 7 boots then it is assigning C to the Windows 7 partition (when I wanted C to be reserved / assigned to the Windows 2000 partition). So I'm not sure if this is "a problem" or if it is "just strange." But before I went any further (i.e., installing apps onto the Windows 7 partition) I wanted to determine if it was an issue. So I tried to boot up the Windows 2000 partition to see if it was "still using" the C letter also ... and that's when I discovered the Windows 2000 partition is no longer bootable. Seems like the Windows 7 installation knocked out the MBR (though I'm surprised, because usually the newer OS preserves the older OS MBR). But before I start thinking about trying MBRfix / Bootfix or anything else, I wanted to see if anyone else had experienced anything like this?

Additional info that may be helpful: When looking at Disk Manager in Windows 7 I see the following info:

Volume Layout Type File System Status

----- ----- ---- ----------- ------

Blank Simple Basic NTFS Healthy (system, active, primary partition)

C:\ Simple Basic NTFS Healthy (boot, page file, crash dump, logical drive)

D:\ Simple Basic NTFS Healthy (logical drive)

E:\ --- DVD drive ----

Under Windows XP it looks like:

Volume Type File System Status

----- ---- ----------- ------

C:\ Basic NTFS Healthy (system, primary partition)

E:\ Basic NTFS Healthy (boot)

F:\ Basic NTFS Healthy

D:\ --- DVD drive ----

Thanks in advance for any ideas / help. I would like to have all three partitions working ...

Not a particularly useful answer, as you don't tell us what happens when you try to boot Windows 2000.

About the drive letters: Windows 7, (and, I think Vista before it) always use C: for the Windows install partition, unlike, say, XP, which respects any other drive letters assigned by another Windows install.

I would have expected that, as Windows 7 has obviously preserved the Windows 2000 entry in boot.ini, it would have been happy to boot into it.

The problem does not appear to be with the mbr, as Windows is still booting from the same active partition. Also, the boot record in the active partition (which has been changed, as Windows 7 uses a different boot manager) seems ok, as you can boot into Windows 7 and Windows XP.