PDFFILT.dll conflicts with AcroRdIF.dll?

Question

Note: the post which led up to this post is here: http://forums.adobe.com/thread/1037849. Anyone truly interested in the subject may want to read that post first!
Both posts refer to the following installations on a computer:
Windows XP Pro SP3 32-bit
Adobe Reader 10.1.3
Windows Search 4 (WS4)
XP's Indexing Service
Adobe's IFilter 6
Outlook 2007.
Background.
1. Adobe Reader automatically instals AcroRdIF.dll, and associated .dlls, for use by WS4 in indexing content of text-based Adobe files (.acrobatsecuritysettings, .fdf. .pdf, pdfxml, .xdp, .xfdf). In the absence of it, or any other installation providing a filter recognised as equivalent to Adobe reader's, in WS4's File Types list against "pdf" "File Properties filter" or "Plain Text Filter" appears. With Adobe Reader installed, "PDF Filter" appears against the file types in question. The Adobe .dlls observed here running with AcroRdIF.dll under WS4's searchfilterhost.exe are:
ACE.dll                         
ACE.dll                         
AcroRd32.dll                 
AcroRdIF.dll                 
AdobeXMP.dll               
AGM.dll                        
AGM.dll                        
AXE8SharedExpat.dll     
BIB.dll                           
BIB.dll                           
BIBUtils.dll                    
CoolType.dll                  
CoolType.dll                  
JP2KLib.dll.
I have left the several instances of some them as seen in Process Explorer.
With no other Adobe filter installed, AcroRdIF.dll can also appear as running under Indexing Service's cidaemon.exe. However, it does no job there. Content of Adobe files is not indexed.
2. Adobe's IFilter 6 enables the Indexing Service in XP Pro SP1 to index content of Adobe text-based files. With Adobe Reader (or Acrobat) not present on the system, but Adobe's IFilter 6 installed, these Adobe .dlls are observed running under Indexing Service's cidaemon.exe:
atmlib.dll                                           
ACE.dll      
AGM.dll
ARE.dll                                                          
BIB.dll        
BIBUtils.dll
CoolType.dll             
JP2KLib.dll
PDFFILT.dll
PDFL60.dll
XMP.dll.
Where some of these bear the same file name as some of the .dlls running under searchfilterhost.exe, in each case their version numbers are earlier.
In addition, in WS4's File Types list, "PDF IFilter"* appears against "pdf" only. However, it fulfils no function with WS4. With only IFilter 6 installed, WS4 does not index content of Adobe text-based files. No instances of PDFFILT.dll or any other of the associated .dlls, bearing the earlier version numbers, have been seen as running under searchfilterhost.exe.
* "PDF IFilter" as against Reader's "PDF Filter".
3. I have marked the .dll file names common to both processes in red.
4. When 2. applies, but 1. is then introduced, "PDF IFilter" disappears from WS4's File Types list, to be replaced by the configuration shown in 1. When 1. applies, but 2. is then introduced, AcroRdIF.dll (if formerly present; it does not always manifest) disappears from under the cidaemon.exe process, to be replaced by the configuration shown in 2.
5. Whichever sequence in 3. has occurred, Outlook's having its connection with WS4 enabled is a constant. Thus if WS4 and Outlook are running, WS4's indexing and search functions also become Outlook's, for indexing and searching Outlook’s .ost and .pst files. (The Indexing Service cannot index content in .ost or .pst files and cannot be integrated with Outlook.)
The issue.
Once IFilter 6 has been installed, it damages Outlook. The damage remains even after IFilter 6 has been uninstalled. The damage can be fixed by running a repair on Outlook.
Effects of the issue.
With Adobe Reader installed and thus AcroRd32.dll and associated .dlls potentially working with WS4, WS4's indexing of and searching for content in Adobe files becomes erratic. Symptoms vary. In some cases, WS4 will not index the content of any Adobe file (in this case, the Adobe .dlls cannot be seen firing up in Process Explorer; they are not called when an Adobe file is reached). In other cases it will only search content in recently introduced Adobe files. Sometimes the filter works, for attachments in this instance, via WS4's GUI but finds nothing when the same search is carried out via Outlook's GUI. And so on. "Erratic" means what it says!
Fix (of sorts).
By trial and error, I isolated the fault to Outlook, as follows:
A.
IFilter 6 is uninstalled
WS4 makes a fresh index
WS4's searching of content in Adobe files remains erratic.
B.
IFilter 6 is uninstalled
Outlook is repaired
WS4 makes a fresh index
WS4's searching for content in Adobe files works reliably.
Questions.
Does anyone know how to fix this? It seems to me that IFilter 6, which is designed for XP Pro SP1's Indexing Service, should make no contact with WS4 and thus with Outlook. But, clearly it does, damaging Outlook. Equally, Adobe Reader should make no impression on XP's native Indexing Service, but clearly it does, its main indexing .dll (AcroRdIF.dll) sometimes appearing under cidaemon.exe. Does the issue arise from both filters sharing a number of .dll file names?
Would my installing IFilter 6 in a separate partition, and not in the regular Adobe folder in Programme Files, next to Reader, help?
Any other suggestions, please?
Related matter.
Regarding the Registry, when IFilter 6 is uninstalled, these files are listed, by the installer, as not unregistered, as they are self-registering files:
ARE.dll, MPS.dll, PDFL60.dll, BIB.dll, ACE.dll, AGM.dll, XMP.dll, CoolType.dll, JP2KLib.dll, BIBUtils.dll (ten in total) -
that is, all of the eleven IFilter .dlls observed as running under cidaemon.exe except PDFFILT.dll and atmlib.dll and with the addition of BIBUtils.dll. I am not sure though that that has anything to do with the issue. PDFFILT.dll is listed in the registry under "DLLsToRegister", here:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\ContentIndex
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\Control\ContentIndex
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ContentIndex.
Again, I am not sure there's any problem there. However, my inexpertise in the Registry prevents me looking further. It strikes me that the fault lies in the presence of two Adobe programmes on the system, both possessing similar indexing and searching facilities.
Views very welcome!!
NB Anyone reading this may wonder why this man is running both SearchIndexer.exe (Windows Search 4) and cisvc.exe (Indexing Service) on the same system. The answer is that the clodhopping hybrid WS4 is only installed to index and search Outlook, which the Indexing Service cannot do. For other searching I find the native Indexing Service, and the Search Companion which works with it (if enabled so to do), much faster and more reliable facilities! I can switch either service on or off very quickly using the sc commands (http://technet.microsoft.com/en-us/library/bb490995.aspx). I should mention here that I have modified the "Search" shortcut in "Start" so that Search Companion fires up instead of WS4 by changing the value of ShowStartSearchBand under HKEY_CURRENT_USER\Software\Microsoft\Windows Desktop Search\DS from 1 to 0 (thanks to: http://johnsadventures.com/archives/2006/11/how_to_default_to_search_companion_with_window s_de/; Search Companion must be running for ShowStartSearchBand to appear). As this is, I think, only a user-accessed shortcut, then I am assuming the change won't have contributed to the current conflict.

Answer 1

I can conclude this query briefly.
After a number of tests, it is quite clear that both PDFFILT.dll and AcroRdIF.dll cannot run satisfactorily on the same XP Pro SP3 32-bit system. Whenever PDFFILT.dll runs, it progressivily destabilises the functioning of AcroRdIF.dll with Windows Search 4 (WS4).
The hook-up between IFilter6 and XP's native Indexing Service is far more robust than the hook-up between Adobe Reader's filter and WS4. As the latter fragments, the the former keeps soldiering on.
Even after uninstalling IFilter6, the Reader/WS4 combo does not recover. Repairing Outlook (see above) may help. But the only certain way to restore Reader and WS4 to good working order, with regard to indexing and searching the content of Adobe files such as .pdf, is, after having uninstalled IFilter6, to uninstal and re-instal both.
Registry entries to observe are:
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.pdf\PersistentHandler]
and
[HKEY_CLASSES_ROOT\.pdf\PersistentHandler].
If {F6594A6D-D57F-4EFD-B2C3-DCD9779E382E} is the value against both, that should indicate WS4 and Adobe are conjoined in unison.
If {B7509D6F-85EE-11d0-AF7D-00C04FD8DC02}, then that indicates the same for Indexing Service and IFilter6.
However, whilst when the latter is the case you can be reasonably sure all is well, the appearance of the other value does not guarantee happiness in the WS4/Adobe camp. Indeed, that situation may well be followed by the two keys disappearing altogether! Stability in the {F6594A6D-D57F-4EFD-B2C3-DCD9779E382E} zone can only occur after uninstallation of IFilter6, as already said above. If it's in situ and so much as hints at running, all is swept before it and its rugged patron, the Indexing Service.
In the blogs and help files (including Adobe's) there is a confusion regarding nomenclature.
Windows Search 4 is a programme added to an existing operating system. It was previously known as Windows Desktop Search. Its service name is: WSearch.
Indexing Service or Content Index Service is built into Windows XP, and has been known as Windows Indexer and similar confusing names which include the word "Windows". Its service name is: ciscv.
Note: this thread concerns itself only with XP Pro SP3 32-bit (extended support for which from Microsoft ends on Tuesday, 8th April 2014 - presumably the date of the last "second-Tuesday" update); search configurations in Vista and Windows 7 are different, as I understand it, and are at any rate ignored herewith.
The two services (WSearch and ciscv) can run independently and carry out their functions separately, which includes of course each cataloguing the same sorts of different files - with the exception of Adobe files. The two services cannot both catalogue the insides of Adobe files. Either one does it, or the other.
The programme Lookeen (paid) may be used apparently as an alternative to WS4 for the purposes of cataloguing emails in Outlook. It is a type of successor to Outlook's Lookout. Their forums/FAQs suggest they only use IFilter6, and have no access to, or use for, the filter in Adobe Reader/Acrobat. Also the filter Foxit (paid) may be more adaptable than the filter bundled with Reader or Acrobat. Both to be confirmed...
Brevity is the soul of wit.