Having won an overwhelmingly dominant position in the personal computer software market, Microsoft Corp is not about to relinquish its grip through carelessness, and is reportedly covering all bases to make sure that Windows NT does not turn out to be a bet-the-company gamble that fails. When it came out with OS/2 and touted it as the answer to every desktop maiden’s prayer, it continued quietly working away at the Windows overlay for MS-DOS – and now thanks its cautious foresight that it did. And we hear that with NT, too, it is making sure there’s a back door to the Alamo: the firm has been telling favoured users that a 32-bit multi-tasking version of MS-DOS is set for testing, with a spring launch likely.