At the time, driver support was the Achilles' heel of 64-bit Windows. The 4074 R2 build was critical for Microsoft and its partners to begin porting existing kernel-mode drivers from the 32-bit architecture to the new 64-bit model. Because 64-bit Windows requires digitally signed kernel-mode drivers, this build served as a test
is thus the last true Longhorn . After this, Microsoft scrapped everything and restarted using Windows Server 2003 SP1 as a new base. Everything after the reset became "Vista." Build 4074 is the endpoint of the original vision. Windows Longhorn 4074 R2 -idx02- 64 bit
Microsoft promised a revolutionary OS: WinFS (a next-gen file system), the Avalon presentation engine, and a completely rebuilt user interface called "Plex." By early 2004, development had collapsed. Build 4074 (compiled on April 23, 2004) was the last build released to the public at Microsoft’s WinHEC conference before the infamous "Development Reset" in August 2004. At the time, driver support was the Achilles'