Symantec Corp is finally ready with a full-blown version of its flagship Norton Utilities for NT. Late to the NT game because of uncertainties that NT on the desktop wouldn’t become a big market quickly, followed by a decision to plough all its resources into Windows 95, Symantec’s Norton developers have been struggling to play NT catch-up for more than a year now. Norton Utilities for NT replaces the rudimentary NT Tools program Symantec released last March, a package more interesting to independent software vendors than end users, with a full-featured $100 utility package that closely matches the form and function of the company’s Windows 95 and before that Windows 3.1 packages. One of the big hang-ups has been perfecting the disk defragmenter in Norton Utilities for NT, a market that tiny Executive Software Inc has until now had to itself.