NT Workstation is unsupported and old and well, not worth it anymore.
It was better than it's non-business oriented alternatives in its day - but
then 2000 came along and NT should have died then.. However, some people
hung on until XP - there is no question, if you plan on using your computer
TODAY, you should have XP over NT Workstation. (They are based on the same
kernel anyway.)
As far as uninstalling - you cannot if you upgraded from NT.
You can find how to do it on Microsoft's site (by searching) for Win 98-ME.