Believe that it is a bug in "regedit.exe", you could query same registry correctly using command line 'reg query /s'. I have tried both upgrade/clean install from download version or MSDN library, all version 1511 got this problem in the 'regedit.exe'.
Your findings also explain why in one machine I didn't have it right after a clean install (second boot), but it appeared a few boots later. Plugging some external hardware might create those long registry strings that cause the search to crash on the new regedit.exe.
After stripping down my hardware all weekend thinking it wasn't a software issue I am formatting for a final time after rebuilding my pc as it looks to be a just bug. I am baffled how Microsoft missed such a thing on the last 2 builds now. I just hope it isn't affecting pc performance, especially in gaming.
I have 2 laptops running 10 1511 and on one the full regedit search completes normallybut on the other it hangs. I checked and both registries have key values with more than 255 characters.
This has been suggested as a solution by someone else on answers dot microsoft dot com: I can duplicate a crash while searching the registry with regedit.exe. The problem area seems to be HKEY_LOCAL_MACHINE\SYSTEM\Setup\Upgrade. This behavior started after the upgrade to 10586. I see this behavior on four different desktops after the upgrade. If I search the registry the search will continue normally up until HKEY_LOCAL_MACHINE\SYSTEM\Setup\Upgrade and then hang. Cancelling the search results in the "registry editor has stopped working" message. If I start a search after that key the search will complete without hanging. I deleted the HKEY_LOCAL_MACHINE\SYSTEM\Setup\Upgrade key and experience no problem with searching.. Can anyone else reproduce this error? I've cleaned up the leftover previous Windows installation and temporary installation files after the 10586 upgrade and I don't see any problems after deleting the key. Just want to make sure there are no unintended consequences waiting to byte me. Thanks. GM
Overwriting regedit.exe version 1511 with the version from Windows 10 10240.16384 solves the problem. Wainting for MS official patch...
Thanks Tovadyk. I exported the key and then deleted it. Searches complete now with no problems. How did you know this is where the search stopped.?
It was not my finding but the user GM on answers Microsoft that suggested it. What is striking how dismissive he Microsoft support people on that forum was when he posted the solution see: answers.microsoft.com/en-us/windows/forum/windows_10-update/regeditexe-search-crashes-after-upgrade-to-10586/f927766a-d991-42ce-a350-a0fa52a38e0b
Normally I use Registra Registry Mechanic for to edit the Registry, which works much better than Regedit from MS. I just tested with Regedit for to delete all keys installed from LevelOne and it were hanging exactly at the HKEY_LOCAL_MACHINE\SYSTEM\Setup\Upgrade Key too! I simply deleted that key and after it were working just fine. The solution posted by @Tovadyk works fine (on my machine). Anyway I'll normally use Registra Registry Mechanic, just good to know a solution for machines which didn't has Registra Registry Mechanik or any other Registry Editor installed, for to solve such problems.
I see what you mean about the dismissiveness of the MS person's reply. I had already tried SFC and it didn't report anything. Good find.
Hah, MS support really are robots. They don't know anything and nobody tells them anything. Most likely Microsoft's coders already know about this crash (thanks to the telemetry ), and a fix is coming sooner or later.
Deleting that key does work, thank you. I also tried replacing the new regedit.exe with the earlier one but the new one was restored automatically ! Micro$oft's 'support' is there to support Micro$oft, not their 'victims'.
There is still an underlying problem with regedit. I did not upgrade, I formatted the new build from scratch so I don't have the upgrade key to delete and I am still crashing on a full search.
Now the regedit search is hanging on the following key. [HKEY_LOCAL_MACHINE\SYSTEM\Setup\SetupapiLogStatus] I bypass it and the search finished. Going to leave it and wait for MS to come up with something.
When I tried after a clean reinstall it didn't crash right away in the first or second boot. But after installing all the stuff, updating, and connecting more external devices other long registry entries that make it crash were created again. Until MS resolves the problem with the .exe, it's bound to happen somewhere the more you use your system. I won't delete registry entries that are perfectly fine until MS solves this problem, it's preferable to use a third party program (or restore the old regedit).
Smart. Just save the newer regedit (e.g., as regedit.old) to put back before installing the patch, if it ever comes.