It was always helpful in 10g to be able to manually enable or disable a component by using the components.hda file, but things have changed in 11g which makes it much more helpful.
The component wizard can always be used to do this, but sometimes the easiest way is to hit the configurations directly. NOTE: this is only a trick for people that know the implications of these changes. Randomly changing hda files will have negative consequences!
One of the key changes is that the WCContent Admin Server & Content Server both run within the same managed server. In 10g, there were two separate jvms that were controlled separately. Meaning, the content server might not have started correctly, but the admin server never was down. That means that the component control was never out of reach.
But, as of 11g, the Admin Server & Content Server both run together within the same Managed Server. That is, they are closely coupled and therefore more reliant on the stability of each other.
If a sketchy component is installed and botches the startup, you might not have the ease of access to flip off the component in order to restart the Managed Server.
Here's where and how that's done in 11g:
Find the following file:
Note the definition is as follows:
The "status" is what we're after. It's values are "Enabled" and "Disabled"
example of a disabled component:
2010_03_19 (build 16)
You can see that a number of values are empty, which is fine. Make sure you don't alter any other values!
After disabling your custom component, you will be able to re-start your content server without any related complications!
Hope this helps out!