You could first try typing:
into the Run box (from Start) and clicking on OK.
When the Services folder opens, scroll down to True Vector Service and ensure it is set to Automatic.
You can alter this if necessary by highlighting the True Vector Service line>Properties and using the menu to enable Automatic. Click OK.
Also try reinstalling ZA's latest version if you don't have it from:
Note that Version 71.078.0 is for Vista.
As you are familiar with ZA, it's probably best to stick with it.