Upgrades will be tier-for-tier, with Vista Home Premium users getting to switch up to Windows 7 Home Premium when the time is right, Vista Business to Windows 7 Professional, and Vista Ultimate users getting an upgrade to Windows 7 Ultimate.

ENGADGET: Windows 7 upgrade details released?

What's more, if you saw the first part of this upgrade diary, then you'll know I was aiming for a trickier-than-average setup, with Windows 8 Pro running on a brand new and untouched SSD, alongside Windows 7 Ultimate running in dual-boot mode on my old HDD.

ENGADGET: Windows 8 upgrade diary: a defiantly successful installation

The J PC runs a Core 2 Duo or Athlon 64 FX, Windows Vista Ultimate, 8GB of DRAM, NVIDIA GeForce 8800GTX 768MB of RAM, 2TB of 7, 200 SATA storage, Blu-ray or HD DVD drive and plenty more trimmings like a 7-inch built-in screen, TV tuner and 7.1-channel sound.

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