"Class not registered" error when initializing COM objects

I have written a VB.Net application which uses the PDFCreator COM interface for capturing print output.  It works fine on my PC, but now I have copied it to another PC that is also running Windows 7 and PDFC 1.7.2.  On that PC, when the program makes its first reference to PDFCreator:

 PDFC_Error  = New PDFCreator.clsPDFCreatorError

This exception is thrown:

System.Runtime.InteropServices.COMException - Retrieving the COM class factory for component with CLSID {BAEE5364-A3A0-4248-96A1-0319B3091160} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).
    Stack Trace:  at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.Activator.CreateInstance(Type type)
at myProgram...

What needs to be done to fix this?