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.