The rebuild is the most recommended fix on the internet and the most mis-sold. It genuinely cures a corrupt index - and it genuinely empties your search for hours while it works. This page shows the steps and tells the truth about the cost, so you start it at the right time, in the right way, for the right reason.
Every forum thread about Outlook search ends at the same button: Rebuild. What the threads skip is the invoice. Rebuilding deletes the entire search catalogue - every mailbox, every document location - and constructs it again item by item. On a small mailbox that is a coffee break. On the 50 GB PST class of mailbox the video talks about, on a mechanical hard disk, it is an overnight job, during which search returns partial results and the PC runs slower than usual. Worth it when the index is corrupt. Pure waste when the real fault was a stopped service.
The confirmation dialog's own warning is the honest summary. The rebuild deletes a catalogue, never your mail.
A rebuild is the correct answer to exactly one diagnosis: the index itself is corrupt. Reach it only after the cheap checks are clean - the status counter read, the Windows Search service running, and the data file confirmed inside the indexed locations. If any of those three is the real fault, a rebuild changes nothing except wasting your evening. No backup is needed for the index itself, because the rebuild never touches mail - but if your PST already shows other corruption signs, that is a separate problem (the scanpst class of repair) and rebuilding will not cure it.
Search results stay partial until the count completes - the yellow 'results may be incomplete' banner is the truthful state of your PC, not an error. Outlook must stay open for mail items to be catalogued, the machine indexes fastest while it is awake, plugged in and lightly used, and a busy disk makes everything slower, including your normal work. Rough honest classes: a few GB of mail on an SSD is usually under an hour; tens of GB on a spinning disk is a start-it-before-dinner job. If you shut the PC down mid-rebuild, nothing breaks - indexing resumes - but the total wait stretches.
One rebuild that fixes search for good was the right call. A rebuild you repeat every week is a symptom you are feeding: something keeps damaging the index or the file underneath it. The usual roots are a PST with growing corruption, a pattern of breaks right after updates, or a hard disk quietly failing - check the disk's SMART health before blaming software again. Repeated rebuilds hide the disease while the mailbox gets worse.
The video performs the rebuild on camera and shows the status screens before, during and after - watch it so the partial-results phase does not scare you into restarting halfway.
Watch Full VideoIt depends on how much there is to catalogue and how fast the disk is. Small mailboxes finish in minutes to under an hour. A mailbox in the tens of gigabytes on a mechanical hard disk can take many hours - plan it overnight. The status window's remaining count, falling steadily, is the only progress report worth trusting.
Yes. Sending, receiving, reading and filing all work normally. Only search is incomplete, and it fills in as the catalogue grows. Keep Outlook open rather than closing it - mail items are indexed while Outlook is running - and keep the PC awake and plugged in so the job finishes in one stretch.
Stop rebuilding and look underneath: a repeatedly corrupting index usually means a damaged PST file, an update pattern, or a failing hard disk. Test the disk's health, consider the PST repair route, and keep the mailbox size honest. A weekly rebuild is the problem announcing itself, not the solution.