7 ==> 10 Upgrade: What happens to Registry & WINSXS

LMiller7 said:

Expansion of the registry is primarily due to third party software.

That is correct. It is also correct for expansion of WINSXS. Long-term (like more than 4 years) expansion typically leads to some sort of corruption and subsequent obscure & hard to resolve problems.

LMiller7 said:

Windows knows nothing and can do nothing about that.

Well I wonder about that. MS does issue WINSXS cleanup routines after each major OS update. These actually work, but take out only the modules that were used by the previous OS and that were replaced by the update. Obviously doing this prevents reverting to the non-updated version of the OS, but who wants to do that anyway?

If that technique can work for the OS itself, why can't it be expanded/enhanced to work for application installs too? Most major apps use the infamous WIndows Installer package, so this would be the perfect place to implement such a capability.

This whole WINSXS issue got started as a means to eliminate the old "DLL Hell" problem in Win3.x. That, in turn, resulted from the concept of sharing DLL's as a means of saving hard disk space. But now disk space is both inexpensive and plentiful. So a simple fix would be to change Windows Installer to install everything in the application's own directories.

The same concept could work for Registry entries. Remember the old INI files? These worked just fine, but for some reason someone at MS thought they needed to be replaced with something "better." Is there anyone who really believes the Registry is better?

LMiller7 said:

A clean install of an OS is usually better than an upgrade, particularly if the installation is old.

Exactly correct. Which is why I plan on scheduling 2 days to get my 10 installation working correctly. That's a ridiculous amount of time I know, but my past experience suggests it's what it will take. I recognize that this is partly my fault - my system has 2 SSD's and 2 HDD's and I have used Junction Links to reposition various files to non-standard (i.e., off my SSD boot drive) locations. Nevertheless, 2 days to do a clean OS install is ludicrous.

bbinnard said:

2 days to do a clean OS install is ludicrous.

Yes it is. It is utterly your own decision though.

It is your only comment I could agree with though.

If you have a better suggestion I'd be most pleased to hear it.

Windows can do nothing about application registry entries because it did not create them. It is not Windows mandate to delete or modify application registry entries. Many application registry keys are created at install time but others are not. Applications use the registry in a wide variety of ways that are known only to the application developer. There are no firm standards for this, only guidelines, and they are frequently ignored. There is nothing in a registry key or value that can reliably identify what application created it.

Windows uninstaller merely acts as a front end to application provided uninstaller that does the real work. Application developers often find it difficult to believe that anyone would actually wish to uninstall their software and for that reason uninstallers often do not receive the attention they deserve. Uninstallers often deliberately leave settings behind for the convenience of users who wish to later reinstall the product. There are other situations where it may not be desirable to remove all traces of the application.

The situation regarding the winsxs folder is quite different. Only the TrustedInstaller account can modify the contents while applications have only read access.

I used to always do clean installs, when upgrading MSDOS and then Windows, because the upgrade of the existing installation was not done well, and caused all sorts of problems.

However, a clean install of the OS and all my programs, and reconfiguring programs and OS to my tastes, took up to a week of my time (yes slow and methodical, that's me).

So this time, after reading that MS was concentrating on improving the upgrade experience, I cloned my Win8.1 to a separate drive, turned off the main Win8.1 drive (so that Win10 couldn't put boot files on it), and upgraded that cloned Win8.1 system and programs. To my delight and astonishment, it worked first time, and I've been using all the programs just as if I were using my main 8.1 setup without any problems.

So, to all those of little faith, give it a try and you too might be surprised.

Bob Frost

I've seen several other posts that relate the same story - so MS must be doing a pretty good job with the upgrade process.

But what happened to the size of your WINSXS and DriverStore directories? Are they bigger? Smaller? Or what?

On my 5 year old Win7.1 system they are 9.5GB and 9.0 GB respectively.