Windows could not update the computer's boot configuration

[grubertm]

I'm running into the infamous "Windows could not update the computer's
boot configuration" error while trying to upgrade my Win XP (Pro SP2
OEM) installation to Vista Business (OEM upgrade version)

* I have checked the UpperFilters entry which still reads PartMgr.

* The compatibility check lists these problems:

Avira AntiVir
ATI Catalyst Control Center
Intel(R) Network Configuration Services
Visual Studio .NET 2003
Windows Messenger 5.1

* In setupact.log it says:

2007-03-22 20:34:57, Info IBSLIB
ModifyBootEntriesLegacy: Not in first boot. No actions to perform.
SetupPhase[1]
2007-03-22 20:34:57, Info IBSLIB
ModifyBootEntries:Setup phase is [1]
2007-03-22 20:34:59, Info IBSLIB
ModifyBootEntriesBCD:System BCD Store does not exist.
2007-03-22 20:34:59, Error [0x0640e4] IBSLIB
ModifyBootEntries:BCDOpenSystemStore failed with unexpected error
code, ec = [c000015c]
2007-03-22 20:34:59, Error [0x0641b8] IBSLIB ModifyBootEntries:
Error modifying bcd boot entries. dwRetCode=[0x3F9]
2007-03-22 20:34:59, Info [0x060216] IBS
CallBack_MungeBootIni:Failed to modify boot entries GLE = 1017
2007-03-22 20:34:59, Info [0x0640ae] IBSLIB PublishMessage:
Publishing message [Windows could not update the computer's boot
configuration. Installation cannot proceed.]

* boot.ini looks like this:

[boot loader]
timeout=2
default=multi(0)disk(0)rdisk(1)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(1)partition(1)\WINDOWS="Microsoft Windows XP
Professional" /noexecute=optin /fastdetect
C:\CMDCONS\BOOTSECT.DAT="Microsoft Windows Recovery Console" /cmdcons

* System is a Gigabyte 8KNXP P4 2.8, 1GB, with one IDE drive that
holds a 1.6GB boot partition and one SATA drive that holds a 76GB
system partition

Where to go from here?

 

[grubertm]

I should add that the boot partition is FAT32, whereas the system
partition is NTFS.

 

[grubertm]

Well since nobody responded I had to solve it myself. I don't know
which step fixed it, but here goes:

- Downloaded EasyBCD and ran it which copied the Vista MBR
- Deleted everything on startup partition except for ntldr, ntdetect &
boot.ini
- Ran diskcheck & defrag

After this procedure Vista was finally able to complete the upgrade.