By Serdar Yegulalp

WINDOWS NT ISN'T for everyone. How do you know if it's right for you? Here's a list of scenarios that typically call for Microsoft's other Windows offerings.

Later for laptops. Windows NT offers some laptop-oriented features, including PCMCIA support, but running NT on a portable remains challenging. Many notebooks can't support more than 16MB of RAM. The slow hard drives and unusual graphics hardware found in notebooks make running NT even more difficult. Stick with Win95 on the road.

Likewise for legacy/specialized systems. Nonlocal-bus or ISA-bus hardware, especially video cards, will further bottleneck NT's performance. Older SCSI controllers, particularly 8-bit models, are being phased out of NT's driver library. NT also suffers from spotty support for EIDE, as developers concentrate on 16-bit SCSI support. Complicating matters, NT can't run a lengthy list of DOS applications, because such software often makes direct hardware calls. To improve stability, NT blocks direct calls to hardware. If you depend on DOS application support, 16-bit scanners, sound cards and joysticks, it's probably easier to run Win95 or even Windows 3.1x than to replace your hardware. In general, if your hardware is more than two years old, you should consider a total upgrade before you run NT.

Cross-platform? Not quite. Microsoft's Windows 95 logo was supposed to indicate and ensure, among other things, that a Win95 application would run on NT. Such cross-platform nirvana has yet to become reality. Microsoft bent its own rules by allowing several Win95 fax programs to earn the logo. That was a questionable move, because many fax programs use TAPI, a telephony API NT didn't support until release 4.0. For stability reasons, NT still doesn't support VxDs and direct hardware calls, which are used by numerous Win95 applications. To compensate, many developers now offer a single CD-ROM containing both Win95 and NT versions of their software. Meanwhile, Microsoft is expected to introduce a new Win32 logo that truly ensures an application will run on both Windows 95 and NT. Even so, there's a long list of Win95 software that just doesn't run on NT.