Uninstalling Oracle 11g manually from Windows 7

I have an Oracle database 11g standard edition installed in my Windows 7 OS. Today I tried uninstalling it to install a fresh Oracle Database 11g Enterprise Edition version. Here are the steps I follow to uninstall my Oracle Database 11g version

1. First step is to stop all the services relevant to Oracle database 11g. In windows 7 navigate from Start->Control Panel->Administrative Tools->Services
2. Click on Oracle Service OracleServiceORACLE_SID,OracleDBConsoleOracle_SID,OracleOraDB11g_homeTNSListener and Click on Link stop. Also stop these services if they are enabled - OracleMTSRecoveryService, OracleJobSchedulerOracle_SID
3. Now its time to remove references from Registry. In Windows 7 search box type regedit. This opens the Registry Editor
4. Click on HKEY_LOCAL_MACHINE. Click on Software. Choose Oracle Folder. Delete it completely. Also Remove HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services and remove oracle relevant entries from there (All will have either Oracle or Ora prefix)
5. Remove the PATH variable from environment variables if set
6. Delete the database files manually from the local machine

In this process of deleting files I got an error which said windows process WmiPrvSE.exe process makes use of certain dlls such as oracell11.dll,oraldapclnt11.dll etc. I renamed the bin folder to bin_old. I restarted the system and it fixed the issue

Reference: Infopediaonilne.com