My desktop currently has the following partition layout:
· C: Windows XP
· D: Windows Vista
· E: Shared (data storage)
I’d been running a Vista/XP dual boot for a while, but recently reinstalled XP to diagnose PC instability, which overwrote the MBR and left Vista unbootable. (Expected, of course.)
However, reinstalling XP didn’t fix the instability — so to narrow down the cause (checking drivers, etc.), I wanted to try booting Vista again.
Unlike XP’s Ntldr, Vista uses BCD (Boot Configuration Data), which makes this complicated.
First: ran the repair setup from the Vista installation disc.
Result: only Vista would boot now.
So I researched how to boot Ntldr alongside Vista’s bootloader.
The Microsoft support page seemed most reliable.
<Steps>
- Use Bootsect.exe to restore Vista’s MBR and boot code. At a command prompt, type: Drive:\boot\Bootsect.exe /NT60 All
Note: Drive is the drive containing the Vista installation media. - Use Bcdedit.exe to manually create a BCD Boot.ini entry for the older Windows version. At a command prompt, enter:
· Drive:\Windows\system32\Bcdedit /create {ntldr} /d “Description for earlier Windows version“
· Drive:\Windows\system32\Bcdedit /set {ntldr} device partition=x:
· Drive:\Windows\system32\Bcdedit /set {ntldr} path \ntldr
· Drive:\Windows\system32\Bcdedit /displayorder {ntldr} /addlast - Restart the computer.
This restored the Vista bootloader at startup, with an OS selection screen for XP and Vista.
But — Vista also blue-screened.
This confirms the instability is hardware-related, not software.
Memory was already tested via KNOPPIX/memtest recently, so that’s unlikely to be the cause.
My current theory: from the very beginning, I suspected the power frequency difference between Aichi and Tokyo might have pushed the power draw above a threshold.
So I removed one cooling fan and a TV tuner card I hadn’t used since the move, just to reduce power consumption a bit.
Things have been running smoothly since then.
Going to keep an eye on it for a while.