Question : SQL 2008 upgrade creates two separate instances

I just did an upgrade from SQL 2005 standard to SQL 2008 standard. During the upgrade process it asks for default or named. When you try to select default so you don't end up with two instances it throws an error saying there is already an instance of that name. I created another name and now when I open SQL 2008 management tools I don't find anything but the system db's. I also now have two completely separate instances of SQL in the services and my old db's are only accessible through SQL 2005 management tools. What kind of upgrade process is this? If I want to do an upgrade I want every db and every remnant of SQL upgraded, not just portions of it so that I have to go to multiple places to find my data. Any help on how to fix this would be appreciated.

Answer : SQL 2008 upgrade creates two separate instances

SCOM:

2.8 GHz or faster
2 GB of RAM or more
50 GB of available hard disk space