What is Windows 7 service dependency tree?

Is there a chart or a list of Windows 7 Profesional built-in services and their dependencies? I manually did this in the past with Windows XP when I had time, but there seems to be a couple dozen more services in Windows 7 and time is not on my side. A quick google search did not yeild anything.

I am trying to figure out why the my event log is showing so many services are start and stopping related to this question.

EDIT: Any Updates?

Solution 1:

A good start would be the services groups. Windows services are willing within groups to load according to them dependencies:

A Service Group is a collection of similar services that are loaded together at startup. Most services that appear in the HKEY_LOCAL_MACHINE\CurrentControlSet\Services subkey are part of a Service Group. Windows NT loads one Service Group at a time. Services that are not in a group are loaded after all Service Groups are loaded.

The HKEY_LOCAL_MACHINE\CurrentControlSet\Control\ServiceGroupOrder subkey determines the order in which Service Groups are loaded. The List value is a REG_MULT_SZ entry that specifies the Service Group order.

The HKEY_LOCAL_MACHINE\CurrentControlSet\Control\GroupOrderList subkey determines the order in which services within a Service Group are loaded. Services in a Service Group are assigned a tag, a unique numeric value within a Service Group which determines the service load order. Each value entry in GroupOrderList represents a Service Group. The value of the entry is a series of tags in a specified order. The first entry in this REG_BINARY value is the number of services in the group, followed by the tags in load sequence. If you look at PointerPort you can see that there are 3 services in the group and that the service with tag 02 is loaded first, followed by the service with tag 01 and then tag 03.

At a service level, the HKEY_LOCAL_MACHINE\CurrentControlSet\Services\ServiceName subkeys contain:

Group - this REG_SZ specifies the Service Group name that a service belongs to.

tag - this REG_DWORD specifies the service load sequence.

DependOnGroup - this REG_MULTI_SZ entry defines the Service Groups which must be loaded succesfully before this service loads.

DependOnService - this REG_MULTI_SZ entry defines services that must be loaded successfully before this service loads.

Solution 2:

Once upon a time I'd found a tool that did exactly what you're asking for (back when Windows XP was new), but I don't have a copy anymore and I can't find it. It didn't handle service groups though, so it would be of limited utility.

The closest thing I can find now is the Windows Service Dependency Viewer. It's not ideal though.