Windows indexing rebuilding nonstop

Alexandre Silva 20 Reputation points
2026-04-07T09:06:31.1+00:00

Hey,

I've been having this problem. My PC is always indexing and at some point goes back to the begining.

The only locations I have in indexing are Outlook, Dropbox and start menu.

I thought it would be because of .pst or .ost large files and I tried repairing and compacting the files but the problem continues.

Whenever I try to add a new location for indexing it starts over and I don't think it's the expected outcome.

Any advice in this situation is highly appreciated.

Thank you.

Windows for business | Windows 365 Business

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VPHAN 44,940 Reputation points Independent Advisor
2026-04-14T14:45:45.7233333+00:00

Alexandre Silva Those file sizes are absolutely the root cause of your ongoing indexing loop. You are dealing with roughly ninety gigabytes of mail data, and because you are running the 32-bit version of Office, the search protocol handler is restricted to a strict two-gigabyte memory limit. When Windows Search attempts to scan and map that massive volume of information, the 32-bit background process completely exhausts its available memory, crashes, and forces the indexer to restart from the beginning. Disabling the Windows service works temporarily because it forces Outlook to bypass the operating system and rely on its own slower, built-in query mechanism, but it does not solve the underlying architectural bottleneck.

To resolve this issue while keeping Windows Search fully enabled, the most effective solution is to uninstall your 32-bit Office suite and install the 64-bit version. The 64-bit architecture removes this memory ceiling, allowing the search handler to easily process massive data files without crashing. If migrating to 64-bit Office is not an option for you right now, you must significantly reduce the amount of data the indexer is forced to read. You can accomplish this by opening your Outlook Account Settings, double-clicking your email accounts, and adjusting the offline cache slider down to six months or one year. This will force Outlook to shrink those massive data files to a manageable size that your 32-bit indexer can process without running out of memory.

Hope this helps :)

VP

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Answer recommended by moderator
Alexandre Silva 20 Reputation points
2026-04-14T15:03:21.33+00:00

Unfortunately switching to a 64-bit office instalation is not possible because of an internal software (PHC) that only allows communication with office via 32-bit installation.

So for now the only solution, is to reduce the offline data cache.@VPHAN thank you for your nonstop efforts to help me with these problem.

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  1. VPHAN 44,940 Reputation points Independent Advisor
    2026-04-08T07:20:44.9233333+00:00

    Alexandre Silva

    Since you are using the 32-bit version of Office, please completely disregard the previous registry steps involving the Wow6432Node directory. That specific registry key is actually required for your 32-bit applications to communicate properly with the 64-bit Windows system. The indexing loop in a 32-bit Office environment is frequently tied to the strict memory limitations of the 32-bit search protocol handler. When this background process attempts to read massive or even slightly corrupted Outlook data files, it exhausts its memory limit, crashes entirely, and forces the Windows indexer to drop its progress and start over from scratch.

    To resolve this, you need to repair the structural integrity of your Outlook data files directly before the indexer attempts to scan them again. Open File Explorer and navigate to your Office installation folder, which is typically located within the Program Files (x86) directory under Microsoft Office and then the root folder for your specific version. Locate and run the built-in Inbox Repair Tool executable named SCANPST.EXE. Browse to your specific .pst or .ost files, which are usually hidden inside your local AppData directory under Microsoft and Outlook. Run this repair process on your large mail files multiple times until the tool reports that no further errors exist.

    Once your data files are structurally sound, right-click the Start button, open your installed apps list, and perform a Quick Repair on your Microsoft Office installation. This action automatically verifies and rewrites the correct 32-bit search filter registry keys without requiring any risky manual registry edits. After the Office repair finishes, ensure your Dropbox syncing is paused just as before, restart your computer, and leave the system completely idle overnight so the Windows Search service can process the repaired Outlook files without hitting memory conflicts.

    Hope this helps :)

    VP

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  2. VPHAN 44,940 Reputation points Independent Advisor
    2026-04-07T09:49:03.3266667+00:00

    Hi Alexandre Silva,

    The continuous indexing restarts you are experiencing are typically caused by the Windows Search service encountering a corrupted database or a file temporarily locked by an active background program. When the indexer hits these conflicts, usually triggered by large Outlook data files or actively syncing cloud folders like Dropbox, it drops its current progress and attempts to start over. Adding a new indexing location intentionally triggers a restart, but the underlying corruption prevents the process from ever completing. To resolve this permanently, you will need to bypass the standard control panel rebuild options and manually clear the core database.

    Begin by opening the Windows Services application and completely stopping the Windows Search service, which forces it to release any locked database files. Open File Explorer, navigate to your main system drive, and access the hidden ProgramData folder. From there, follow the path through Microsoft, Search, Data, Applications, and finally the Windows folder. Inside this directory, locate and delete the Windows.edb file or clear the entire folder contents to force your system to generate a completely clean database upon the next restart. If you are running a 64-bit version of Office, a known registry conflict with the 32-bit search protocol handler can also cause these crashes. Open the Registry Editor and navigate to the Wow6432Node directory inside both the HKEY_CLASSES_ROOT and HKEY_LOCAL_MACHINE hives. If you find the CLSID folder named {F8E61EDD-EA25-484e-AC8A-7447F2AAE2A9}, you can delete it from those 32-bit nodes to ensure Windows correctly utilizes the 64-bit search protocol handler.

    Before you restart your computer to initiate the new index, ensure you pause your Dropbox synchronization. Cloud syncing applications frequently lock files while checking for server changes, which can immediately crash your freshly running indexer. After restarting, leave Dropbox paused and keep your PC powered on and completely idle overnight. The search indexer runs at maximum speed only when the computer is inactive, so providing it with an uninterrupted overnight window will allow it to successfully build a stable catalog of your Outlook and local files.

    Hope this answer brought you some useful information. If it did, please hit “accept answer”. Should you have any questions, feel free to leave a comment.

    VP

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  3. AI answer

    2026-04-07T09:06:50.01+00:00

    Continuous rebuilding of the Windows/Outlook search index typically indicates a problem with the index store or with how Outlook data is being indexed. Use these steps to stabilize it:

    1. Let indexing complete when possible
    • The indexer only runs at full speed when the PC is idle. If large Outlook data files (.pst/.ost) or many Dropbox files are included, indexing can take a long time and appear to “restart.”
    • Open Indexing Options and confirm the status shows “Indexing complete” at least once after leaving the PC idle for an extended period.
    1. Rebuild the Windows Search index If indexing never completes or keeps looping, rebuild the index:
    2. Close Outlook.
    3. Open Control Panel.
    4. Choose Indexing Options (or search for Indexing and select Indexing Options).
    5. Click Advanced.
    6. On the Index Settings tab, under Troubleshooting, select Rebuild and confirm.
    7. After the rebuild starts, leave the machine on and as idle as possible until the status shows indexing is complete.

    This clears a corrupted index catalog and forces a clean build, which often stops the constant restart behavior.

    1. Rebuild the Outlook Instant Search catalog If the issue is mainly with Outlook items:
    2. Close Outlook.
    3. Open Control Panel → Indexing Options.
    4. Confirm Outlook is listed under Indexed Locations.
    5. Select Advanced → Index Settings → Rebuild.
    6. Reopen Outlook and allow time for Outlook items to be fully re-indexed.
    7. Avoid changing indexed locations during rebuild Adding or removing locations while the index is rebuilding can cause it to restart. Wait until Indexing Options shows that indexing is complete before changing locations (for example, adding more Dropbox folders).
    8. If using 64-bit Office and Outlook search is still unstable If Outlook search returns no or inconsistent results after the rebuild and Office is 64-bit, follow the registry-based fix for 64-bit Office search issues:
    9. Close Outlook.
    10. Open regedit and verify these keys exist:
      • HKEY_CLASSES_ROOT\CLSID\{F8E61EDD-EA25-484e-AC8A-7447F2AAE2A9}
      • HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F8E61EDD-EA25-484e-AC8A-7447F2AAE2A9}
    11. Delete these keys if present:
      • HKEY_CLASSES_ROOT\Wow6432Node\CLSID\{F8E61EDD-EA25-484e-AC8A-7447F2AAE2A9}
      • HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\CLSID\{F8E61EDD-EA25-484e-AC8A-7447F2AAE2A9}
    12. Restart Windows.
    13. Open Outlook and wait for indexing to complete (this may take hours).

    Editing the registry is risky; back up the registry first as described in How to back up and restore the registry in Windows.

    1. Rebuild Windows Search index if OneDrive/Dropbox content is involved If Dropbox (or other synced folders) is included and search status seems stuck or incorrect, rebuild the Windows Search index again from Indexing Options → Advanced → Rebuild, and let it run while the PC is idle.

    If, after a full rebuild and a long idle period, indexing still repeatedly restarts or never finishes, this typically indicates a deeper Windows Search or profile issue and may require further OS-level repair or profile recreation.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

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