Ignoring the millions of users now using laptops, Microsoft will not support so-called "legacy" laptops with Windows NT 5.0. The next release of NT--due late next year--disables power management, socket services, and Plug-and-Play features from most laptop computers.
Most laptops today use a power management feature called APM, but Microsoft refuses to enable APM support in Windows NT 5.0, going instead with a newer power management feature called ACPI (Advanced Configuration Power Interface). This means, for example, that a Dell Latitude notebook that I bought just this June will not work with Windows NT 5.0, though NT 4.0 works fine.
"Early ACPI adopters have a big plus," said Carl Stork, a general manager of Microsoft's Windows Platform group. This is another way of saying that APM-based laptop users are screwed, since these machines will not work properly with Windows NT 5.0. Another problem for APM laptops: Windows NT 5.0 will not properly recognize docked/undocked situations, resulting in numerous error messages at boot-up and/or an unusable system.
There may be a small light at the end of the tunnel, however: some unnamed laptop manufacturers are working with Microsoft to provide a new flash BIOS that would enable the new features. Not many systems will be upgradeable this way, unfortunately.
"It's going to be like playing Russian roulette if you decide to go from NT 4.0 to NT 5.0 on \[existing\] notebooks," said Rob Enderle, a senior analyst at the Giga Information Group.