>When I update a COM+ DLL, I go into Component Services and stop the component.

Dude, you're doing by this *hand*?! Write a project hook that takes care of this when you build.

>How can I prevent the COM+ component from being reloaded into memory until I explicitly start it?

Assuming your COM+ application name is "DevCon":

LOCAL oCat as "comadmin.comadmincatalog"
oCat = createobjectex("comadmin.comadmincatalog",'','')
ocat.GetCollection("Applications")
oapps=ocat.GetCollection("Applications")
oapps.populate()
LOCAL myapp
FOR EACH app IN oapps
	IF app.Name = "DevCon"
		myapp = app
	Endif
Endfor
myapp.Value("IsEnabled") = .f.

*-- Do what you need to do here

myapp.Value("IsEnabled") = .t.