AFAIK, it would be illegal for you to distribute the solver files
yourself. If the recipient has the product installed, the code below
should work. It has been tested *very* lightly. It also assumes the
necessary security permissions are available. Obviously, it would
benefit from additional code to respond gracefully to the absence of
Solver.

Sub testSolverRef()
On Error Resume Next
ThisWorkbook.VBProject.References.Remove _
ThisWorkbook.VBProject.References("Solver")
ThisWorkbook.VBProject.References.AddFromFile _
Application.AddIns("Solver Add-in").FullName
On Error GoTo 0
End Sub

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article ,
says...
What can be done to make a VB solver invoked routine work across versions of
Excel? Currently the VB code that I write in an Excel 2000 app will not fly
when I open the sheet in Excel 2002 nor will a 2002 app fly when brought over
to a 2000 excel installation (the VB code however is the same). I realize
that the solver file and probably the solver.dll being used by these 2
versions is different, but how can I get around this without distributing a
solver.xla and solver.dll file to force into some other user's machine with
every app. I send?