Need a vpn software to be done, i will be running the client software on multiply windows servers different locations which will have all linked to one GUI software.
you need to do:
1- Client back connect software which will be installed on windows computers.
2- Server software which will collect all online clients connections for monitoring, add, delete user.
3- GUI setup software which will be provided for customers to use with attractive design and country based option to change whole computer connection to it.
Don't bid if you cant deliver this with a professional support!