Post by Lawrence D'OliveiroPost by CrudeSausagePost by Lawrence D'OliveiroPost by ChrisAre you a developer with intimate knowledge of the inner workings of
Windows? Windows doesn't work that way mostly for marketing reasons.
Nobody knows how Windows works, not even Microsoft’s own engineers.
Who in the world, inside or outside of Microsoft, can answer yes to the
first question? Nobody.
I would be surprised about this considering how they rewrote most of it
in the mid-2000s.
They tried to. Remember “Longhorn”, which became Windows Vista? They were
promising a whole bunch of new major technologies, none of which
eventually shipped. Remember why it was so late? Because somebody had the
bright idea of writing core parts of it in Dotnet. Which turned out to be
a really bad idea. So the infamous “Longhorn Reset” involved chucking out
and replacing all that Dotnet code. And even with the delay, they still
had to rush to get it out. Hence all the bugs and inefficiencies and
instabilities and other trouble.
Why does Windows need to reboot about 5 times during an install? Because
nobody at Microsoft knows to reliably shut down and restart their own
services, so it’s easier just to reboot everything.
https://learn.microsoft.com/en-us/troubleshoot/windows-client/setup-upgrade-and-drivers/windows-10-upgrade-issues-troubleshooting
1) Downlevel phase: ... this phase runs on the source OS <=== can pop the DVD or .ISO after this reboots
The OS may download patches for Windows Update materials or similar.
the installer may restart itself (no reboot) after patched.
[This is the "media copy" phase. Decompression of install.wim happens here.]
2) SafeOS phase: ...computer is booted into Windows PE during the SafeOS phase
Now the computer has a known good OS, to continue the installation process
The logfiles go in a different place now. There will be Windows and Windows.old .
The datestamps on (1), versus (2),(3),(4), one uses local time, the other
uses UTC.
3) First boot phase: ...failures... almost exclusively caused by device drivers.
4) Second boot phase: ... system ... running ... target OS.
and somewhere in there, is the "Migration phase", where programs are reinstalled
one by one. For example, when I Repair Installed a Win10 on the Test Machine
yesterday, and walked away, when I came back the screen was open, and the Logitech
webcam install program was asking for EReg (registration information). I could not
tell if the Repair Install had finished or it had bombed out (as the version of
the OS does not change during a Repair). I removed the Logitech package, and
re-ran the Repair Install, and it finished pretty quickly the second time. It
likely did not roll back after all (from the first attempt).
This is why there is a folder full of .msi files . It is used for program removal
normally, but also serves as the base for program reinstall on a Repair Install.
The Windows.old file is not as it seems. It is more than a Windows file, and
it contains all the materials needed during a rollback. Including some kind
of Program Files content. That is just in case you have some weird idea of
"renaming folders" and pretending it is the old system. Don't do that :-)
That stuff is there for a reason, it can be used for a reversion request by
the user, and the materials are erased on their own after ten days have elapsed.
You don't need to use CleanMgr.exe to remove Windows.old properly. *Do not* use
the Trash Bin for removal either. There is a command line sequence which
it is claimed, can do the removal (a little icacls magic I would assume). On
one occasion, some invalid characters were in a couple of places in Windows.old,
and then the command line method is going to fail.
The https://learn.microsoft.com site has the technical contents. One of the
problems, is getting the Google search syntax "just right" to get the most
topical page from that site. It took me around eight tries to get the above link.
The wrong keywords, will leave you showered in junk.
IT people have to be familiar with WADK, DISM and Sysprep and building reference OS
images for Enterprise setups. Then mass deployment of image to thousands of
machines. A lot of the educational materials are there to help the IT people.
Paul
