Description
Quartus® II keeps a cache folder of older version components in C:\Documents and Settings\<username>\.altera.quartus\ip\9.1\ip_search_path\user_components.ipx. Delete this cache if you do not need them anymore.
If you cannot find this cache folder in C:\Documents and Settings, check the location of your HOME environment in System Properties -> Advanced -> Environment Variables. Find this cache folder location according to the HOME environment setting.