Summary of "The MojoPac Windows Vista Upgrade Won't Work - Here's Why (Followup)"

Topic

Follow-up analysis of attempting to upgrade a MojoPac “portable Windows XP” instance on an iPod to Windows Vista — why the upgrade fails and what MojoPac actually is.

What MojoPac is (technical summary)

MojoPac is not a full virtual machine. It is a sandbox/overlay environment that presents a Windows XP–like C: drive from a USB device while relying on the host PC for most system files and functionality.
Launch mechanism:
- An executable on the device (start.exe) launches the MojoPac environment.
- Many Windows system binaries are not actually stored on the USB device (for example, many system32 .exe files are missing).
The apparent size of the Windows folder inside MojoPac is artificially inflated because MojoPac maps or references host files into the sandboxed view rather than containing a full standalone copy.
Because MojoPac is not a standalone Windows installation, it could be distributed without bundling a licensed copy of Windows XP (unlike a true VM image).

Why a Vista upgrade fails

Vista setup cannot see a usable system or partition drive inside the MojoPac environment. Typical errors encountered include:

“No drives were found”

“Upgrade has been disabled — not enough space to upgrade Windows on partition C”
These errors occur because:
- MojoPac does not expose a real, writable system partition that Windows setup can upgrade.
- The environment is not a full installation, so in-place upgrade logic and the installer’s disk detection fail.
A clean install also won’t work because the MojoPac environment lacks the required drive/installation context.

Tests performed and results

Run Vista Home Premium upgrade DVD from within MojoPac
- Setup starts but fails with “no drives found” / upgrade disabled — in-place upgrade is impossible.
Insert Office 2003 CD and observe installer
- The Office installer autoran on the host after being launched inside MojoPac.
- This behavior was reproduced and determined to be normal Windows autorun behavior on the host, not definitive proof of a MojoPac “leak.”
Selecting “Turn off computer” inside MojoPac
- Only logs off/unloads MojoPac; it does not power down the host PC.
Run MojoPac on a Windows 10 host
- Fails with compatibility errors such as “currently logged in as a limited user” and “requires that only one user be logged in at a time — please reboot.”
- In practice, MojoPac is incompatible with newer Windows versions.
Run MojoPac on a Windows XP virtual machine
- Works as expected.
- Programs and settings installed in MojoPac persist when the same MojoPac image is used on other XP hosts; some UI/theme behavior may vary slightly.

Bugs, compatibility, and lifecycle

RingCube (MojoPac developer) acknowledged a known bug where modifications to MojoPac system files could be reflected on the host PC — i.e., isolation was imperfect. They stated it would be fixed in a future version, but that fix apparently never arrived.
MojoPac was designed for Windows XP hosts and is incompatible with newer Windows versions (Vista, 7, 10). Upgrading the sandboxed XP to Vista is not possible.
The free distribution of MojoPac is consistent with it not containing a full Windows XP installation (hence no bundled Windows license).
MojoPac has been discontinued.

Practical takeaways

MojoPac is useful for running a portable XP-like user environment from USB on XP hosts for legacy apps, but:
- It is not a true virtual machine or independent OS installation.
- It is unsuitable for OS-level operations such as in-place upgrades (e.g., XP → Vista).
- It may be risky due to known isolation bugs (changes might affect the host).
- It is incompatible with modern Windows deployments (no Vista/Windows 10 support).

Primary sources / speakers referenced

Video narrator / creator (YouTube video host; unnamed in subtitles).
RingCube (MojoPac developer) — referenced via Wikipedia and cited (original site no longer available/archived).
Wikipedia page (citing RingCube) and Wayback Machine (attempted retrieval of archived RingCube pages).
Test platforms mentioned: Windows XP host PC (Dell Latitude D610 referenced), Windows 10 PC, Windows XP virtual machine; Windows Vista Home Premium upgrade DVD; Office 2003 CD.