Microsoft, which became the world's largest personal computer software maker by selling MS-DOS, is now trying to repeat the success story through its new operating system software.

Called Windows NT, the program, which controls the working of a computer, bears striking resemblance to Microsoft Windows, the popular graphical interface to MS-DOS.

But the look is where the similarities end. Underneath its icons-and-windows skin, NT is a whole new organism.

The first thing that distinguishes the two programs is that NT is a stand-alone operating system, while Windows runs on top of MS-DOS. Because its core sections (known as the kernel to computer professionals) were written from scratch, NT is free of all the quirks and limitations for which MS-DOS has gained much notoriety.

One area in which NT shines compared to its MS-DOS-based cousin is in multi-tasking, or the ability to run more than one program at a time.

Of the two types of multi-tasking, the better kind assigns each task to its own processor so the programs run simultaneously in the truest sense. But often there are more tasks than available processors. Most PCs, after all, are equipped with only one brain. In the second type of multi-tasking, an operating system creates an illusion by "juggling" the programs very quickly.

Both NT and Windows feature multi-tasking of this second sort. But NT does a better job as its task assignment algorithm is better. What all this means to the user is that while in NT you can format a disk and download files from your husc account at the same time, this is impossible with Windows.

NT goes a step further by also supporting true multi-tasking--when it knows that your computer has more than one CPU. In this case, all the processors are called in to execute programs and the computing power is increased.

NT has also been designed to be network-savvy, making connecting PCs to networks--be they your local Ethernet or the global Internet--an easy job.

In an attempt to establish NT as the standard operating system for both PCs and workstations, Microsoft has made it available not only for Intelbased PCs but for computers based on other processors such as DEC's Alpha chip and Silicon Graphics' MIPS processor.

Well, NT sounds great. So what's the catch?

It turns out that to use NT, you need a lot of RAM and a large hard drive, not to mention a lightning-fast microprocessor.

That translates into at least a 486SX processor running at 25MHz, eight megabytes of RAM and a 60MB hard disk for PCs.

But these are just the minimum requirements. Running NT on such configurations is not unlike putting a Volkswagen Beetle engine inside a Ferrari: sure you can drive, but it's more like crawling than racing.

So taking advantage of NT's powerful features--or just making its performance acceptable--calls for something like a 486DX2 microprocessor (i.e., the "double-clocked" type), 16 MB of RAM, and as big a hard drive as you can lay your hands on. A CD-ROM drive, albeit not yet a necessity, will certainly make your life under NT more enjoyable, as will a large color monitor that supports Super VGA video.

NT is not the only powerful operating system for Intel-based PCs on the market these days. IBM's OS/2 2.1, probably NT's most serious competitor, features robust performance, excellent multi-tasking capabilities and flawless execution of MS-DOS programs. But its installation is a pain--you have to deal with 25 disks!--and it lacks a great many device drivers to support a wide class of peripherals.

There is also Steve Jobs' NeXTStep 486. Requiring even more computer power to run than NT, NeXTStep brings the much-acclaimed object-oriented interface of the now-defunct NeXT computer to PCs. While it probably features the best user environment of any computer, its hefty demands on the underlying hardware have kept the PC masses away.

Last but not least, SunSoft, the software unit of Sun Microsystems, has developed Solaris, a well-designed system built on the famed UNIX operating system. It's likely to appeal to some UNIX diehards but may not attract a large following.

While NT may not be the best operating system for the PC--I would recommend OS/2 2.1 if your computer can run it--it has Microsoft's marketing muscles behind it and stands a very good chance of becoming the next standard of personal computer operating system.

But the wide acceptance of NT may be hindered by its high demands on the hardware and the $499 price tag. For most PC users, MS-DOS is still the best environment available.

Haibin Jiu '94, associate photography chair of The Crimson, is the former president of the Harvard Computer Society. His column appears Tuesday.