Dui.

If the classes were not taken then you violated a term of your probation.  A bench warrant for your arrest was probably issued.  While the authorities will not (and indeed have not) pursued you on this, if you are stopped for something as simple as jay-walking it could all turn up and you could be taken into custody.  This could even be discovered in an employment background check.

What you need to do now is to consult with an experienced DUI attorney; find one in the area where the warrant would have been issued.  They will know best how to have you "turn yourself in"; they will have local contacts that they can utilize to your advantage.  But do something quick; if indeed a warrant was issued it will not expire.