How to get notification/alert window,while working in c#

Question

Hi

How to get notification/alert window,while working in application C#

I want to get meeting schedule alert(particular logged in user if he has meeting) every one hour before the meeting.

I am getting data from database.

The process is executed using 'exe' application using windows services

but I do not know to execute windows services and call the 'exe' application and make alert window

how to map the  two.

 

Can you please help me to find the solution

Thanks and Regards

Ramachandran