[Perineum]

Or make the steam service (if it is one) have a dependency on the network or whatever, but I forget how to do that right now....

edit: here it is:

1.Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es and locate the service that you need to set a dependency for.
2.Open the 'DependOnService' key on the right side. If the selected service does not have a 'DependOnService' key, then create one by right-clicking and selecting New > Multi-String Value.
3.In the value field, enter the names of all services that the current service will depend on. Each service name must be entered properly and on a separate line.
4.Click OK, close your registry and restart your machine.

Or...

Try doing the following and see how you get on:

1. Open the appropriate Group Policy object for the computer or computers on which you want to implement the change.
2. In the left pane, click to expand the following items:
   • Computer Configuration
   • Administrative Templates
   • System
   • Logon
3. Double-click the Always wait for the network at computer startup and logon setting.
4. Click Enable, and then click OK.