Can you open the solve tool without adding any thing to ArcMap? If it crashes then it could be an installation problem.
If yes, add your network dataset and then open the tool. It should open as the solve tool does not look for a network dataset. It operates on network analysis layers such as route.
If the above works, then create a route layer and do not add or change it and then open the solve tool. Does it work or crash? If it crashes, then you should call Esri tech support and have them look at this issue.
Jay Sandhu