Desktop CPU: 3 GHz Intel Pentium 4 processor with HyperThreading Technology 530 (or higher) or 3 GHz Intel Xeon processor with 2 MB L2 cache, or AMD Athlon 64, Sempron, or Opteron 100, 200, or 800 processor, single or dual-core versions.
Mobile CPU: 1.86 GHz Intel Pentium M processor 750 (or higher), or AMD Turion 64 Mobile Technology, Mobile Sempron, or Mobile Athlon 64 processor.
RAM: 512 MB of RAM or more, all platforms.
I'm dissapointed by these hardware Requirements released by microsoft. These are subject to change but this is what we can expect. My CPU is a 2.40 Pentium 4 and I have 480 RAM. I can upgrade my ram but I'm the type of persion if I need to update my processor I'm just gonna build a new PC. These are pretty high tech and I would guess that computers that are made in 2005 may have to be on the higher end to run Longhorn smoothly. This is no reason to stay behind and not update with the times though. If the future needs a certen level of power from our hardware I suggest it is time to update.
I'd also like to add Longhorn BETA 1 will be released sometime this July.