Sometime you do some mistakes which look very distractive, and seem that you have done something which can be a terrifying, but most of the time solution or recovery is a matter of few clicks. One mistake is that if you have deleted SCOM Default Management Pack, while you were removing another Management Pack which has the dependency of Default Management Pack. Once Default Management Pack is deleted then what will you see… are you missing Active Alerts, Discovered Inventory and a few other things under the Monitoring pane?
Remember before deletion of Default Management Pack monitoring used to look like this?
And after deleting Default Management Pack, I bet, if you have deleted you are familiar with this....
So relax your panic no longer, because it is very easy to fix, as I said earlier some a matter of few clicks. The same thing happened to me, and I spent few hours or so trying to find out how to fix this issue. I found fragments of information, and finally I sort matter and fix it.
When you delete the default management pack (for whatever reason), you also delete some of the default views that are associated with it.
The solution is quite easy – you have to manually import the Default Management Pack. Import a management pack as you normally would, but navigate to the directory where you have System Center Operations Manager installed. Look for the Microsoft.SystemCenter.OperationsManager.DefaultUser management pack. In my server tis was located in C:\Program Files\System Center Operations Manager 2007.
Click Open, then click Install (as per the below diagram).
Then click Close
After that Close the SCOM Console and Re Open it,
So be happy, you got all your SCOM views back again.
Removing SCOM Management Pack Dependencies (http://blogs.technet.com/b/meamcs/archive/2011/08/21/removing-scom-management-pack-dependencies.aspx)