
Hi @Nelson Miguel Ventura Brites Correia ,
Did you get any error message?
What version of Office did you use?
Can you enable Solver add-in from Excel?
If you're using Office 365, please go to this location:
C:\Program Files\Microsoft Office\root\Office16\Library\SOLVER
and check if you can find SOLVER.XLAM and SOLVER32.DLL
Try to copy Solver.dll file in the %SystemRoot%\System32 folder and check the result.
Try this method and let me know if you need more help about this problem, I'm glad to help you.
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