illegal operation attempted on a registry key that has been marked for deletion sharepoint search 2007

Troubleshot steps to fix the issue:

1. Stop office serach service in CA 

2  Stop the OWSTIMER service on ALL of the MOSS servers in the farm.
3. Stop Proxy server settings in search administration (Un check check box)
4. Started the Search Query and Site Settings Service on all the servers in the farm that query happens on (in Central Admin, Manage Services on Server)
5. IIS reset in All servers.

Clear the SharePoint Configuration Cache

To clear the config cache on the farm, follow these steps:

1. Stop the OWSTIMER service on ALL of the MOSS servers in the farm.
2. On the Index server, navigate to:                          

Server 2003 location: Drive:\Documents and Settings\All Users\Application Data\Microsoft\SharePoint\Config\GUID and delete all the XML files from the directory. 
Server 2008 location: Drive:\ProgramData\Microsoft\SharePoint\Config\GUID and delete all the XML files from the directory.

3. Delete all the XML file in the directory. NOTE: ONLY THE XML FILES, NOT THE .INI FILE.
4. Open the cache.ini with Notepad and reset the number to 1. Save and close the file.
5. Start the OWSTIMER service on the Index server and wait for XML files to begin to reappear in the directory.
6. After you see XML files appearing on the Index server, repeat steps 2, 3 & 4 on each query server, waiting for XML files to appear before moving to subsequent servers.
7. After all of the query servers have all been cleared and new .xml files have been generated, proceed to the WFE and Application servers in the farm, following steps 2, 3, 4 and 5 for each remaining server.

The protocol handler cannot be found. Check that the handler has been installed.

Troubleshooting:

Ø  We could see that the Search Service was started on only 1 server

Ø  Checked the search service was started and that the indexer was assigned è all ok

Ø  Decided to move the entire search function on the other WFE in order è same behavior

Ø  Decided to run a clear configuration cache as explained here:  http://blogs.msdn.com/b/josrod/archive/2007/12/12/clear-the-sharepoint-configuration-cache-for-timer-job-and-psconfig-errors.aspx  è same behavior

Ø  Ran psconfig –cmd services install è same behavior

Ø  This had to be related to the search service.

Ø  Checked following registry keys: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office Server\12.0\Search\Setup\ProtocolHandlers è OK

Ø  Checked: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office Server\12.0\Search\Applications\<GUID> \Gather\Portal_Content\Protocolsè we were missing some entries here

Ø  Decided to register the .dll again for the search: regsvr32 "%CommonProgramFiles%\Microsoft Shared\web server extensions\12\BIN\mssph.dll"

Ø  Restarted the search service

Ø  Started a full crawl and we could see it was crawling successfully.

Ø  Checked on the other server and we could see that the entries were missing there from the registry too.

Ø  Ran regsvr32 "%CommonProgramFiles%\Microsoft Shared\web server extensions\12\BIN\mssph.dll"