And start deleting items one by one. Run a registry cleaner (I like CCleaner) recursively until it can't find anything else. Reboot. Go back to the folder and try deleting anything that was denied in the first round. Run your registry cleaner again.
The most likely reason that you can't delete the folder is that One Care has a process running. If you can find the process and kill it, do so. Another thing is that it is set to run at startup. Kill that too.
Two things- If you use CCleaner, make sure that you run it recursively. It will pick things up in consecutive passes. Also, it will prompt you to back up your registry. DO THIS. I put the backup on the desktop so I can find it again. You only need the first backup.
You can find CCleaner (free download) at http://www.ccleaner.com.
Good luck!