ANYONE who has used a PC regularly will know the moment. The time when a programme locks up and the screen goes a pale shade of blue, signalling an imminent collapse.

Pressing the "Esc" key doesn't work. "Ctrl-Alt-Del" only comes up with a message that if you do it again your PC will re-boot. Cursing doesn't help, nor does shouting or shaking the keyboard violently.

If you are lucky, some of your work may have been saved. If you are not, then all has been lost. There's no option but to switch off and start again.

Sadly, this situation is so familiar to PC users that millions of us have just come to accept it as a matter of fact. If cars were so unreliable, showrooms would be under siege by angry drivers demanding their money back.

The problem is usually a conflict between a software programme and the operating system - the foundations upon which your PC operates - installed on the machine.

Windows, the operating system used on most of the world's computers, is remarkably easy to use but not without its flaky characteristics.

Apple Mac users - long used to a stable operating system - have pointed to the PC's relative instability as a sign that their machines are superior.

And Microsoft has had three attempts at making Windows 9.x a more robust computing environment. But, if the truth be told, there's little practical difference between Windows ME and Windows 95.

This summer, Microsoft is coming back for yet another try and, this time, it is convinced it has the problems licked.

The new version, called Windows XP, takes the best bits of Windows 9.x and marries them with Windows NT, the version sold to businesses which does not crash as much as Win 98/ME.

As usual there is good news and bad news.

The good news is that XP should not crash as much. Users of early pre-release versions say it is every bit as good as the Mac OS. Even when it does freeze, the error message it flashes up on screen is a polite explanation rather than a screen of techno garble.

The downside is that the convergence between 9.x and NT means some early Windows programmes (and DOS games) probably won't run on a PC using Windows XP. Just how big a deal this is, remains to be seen. You can be sure they are burning the midnight oil at Microsoft's HQ in Seattle to narrow the gap.

XP also marks a further move towards PC integration with the Internet started with Win 98.

What are the benefits? One example Microsoft likes to use is downloading music. With XP, you can download an album and the PC will also search the net for the album cover and sleeve notes automatically.

XP also includes a built-in firewall to protect your PC from Internet hackers, MP3 converters for digital tunes, digital camera connectivity and CD-burning software.

So it's looking pretty good and Microsoft is so convinced it has come up with a winner that it's betting a huge amount of cash on XP's success.

Come Christmas, provided XP hasn't been delayed, we can expect every home PC to be faster, more stable and more obedient. Roll on XP.

Published: 21/04/01