HUGE %WINDIR%\Installer folder

My wife's mini-ITX PC was upgraded from 7 to 8 to 8.1 to 10. The installer directory has over 36 GB of stuff in it (mostly smaller installer files for what looks like OS components, some dating back to 2013). I see from online research that it's not a good idea to prune this directory. My recent clean install machines have between 1 and 2 GB of stuff in that same directory. I think that means it's time for a clean install on this PC. What advice or insight can the community offer on this subject?
The machine is running well (it's a light-duty machine only that the boss uses primarily for surfing the web and reading/writing email). Am I just obsessing over nothing here? Again, advice and insight much-appreciated.
--Ed--

Hi, these are installer packages which
a. support e.g. 'Change' options in the Control Panel, Programs and Features, for programs you've installed.
b. are for lower level system utilities.

Ideally if a program is installed, the corresponding msi would be deleted, but this doesn't always seem to happen. Also, I note some msi's exist for installed programs, but a Change option isn't offered. Hmm.

If you were to organise the folder by size, and hover your mouse over the largest 10, for example, or even double click one to launch it to see what it is if unsure, you could then see if the program is still installed. If not, you could delete the msi.

I just found I'd 2 copies of the same version of Macrium, 3 versions of a program I no longer have installed at about 70Mb each.

Thanks Dalchina: I had noticed quite a bit of redundancy. I assume that means I can selectively prune out older/obsolete versions. Some stuff in there goes back to early 2013, and has been superseded by newer versions of the same application or utility. I always keep an image backup handy, so I'll try some selective experimentation and report back here. Thanks for the input and insight. Always enjoy your prolific posts here on the forums.
Best wishes,
--Ed--

Install patchcleaner - best tool I know for clearing this sort of stuff - safer than using ccleaner.

A remarkably elegant error message... nice!

Ran it on my machine, and it found 146 MB of orphaned files in 1.4 GB of "stuff." No elegant error messages here, tho -- nice call, Dalchina! -- now running on the boss's PC. It's going to take a while because of the 36.5 GB of "stuff" in that folder. Will report back on those results when it's complete ... 15 minutes later: 30.43 GB removable/relocatable. Opted for the safer relocation to the 1 TB external HDD attached to her PC. Now moving ...



Took another 15 minutes to relocate everything. Now, WinDirStat reports that C:\Windows\Installer is down from 36.5 GB to a relatively svelte 6.1 GB. Great stuff!

Thanks Cerberus! I'll be digging in more deeply and writing about this for my Windows Admin toolbox series soon, I believe!

Everything said, this is exactly why I posted a plea for help and insight here. I knew there had to be a way to deal with this, and indeed there was. Thanks again to one and all.

Best wishes,
--Ed--

EdTittel said:

Ran it on my machine, and it found 146 MB of orphaned files in 1.4 GB of "stuff." No elegant error messages here, tho -- nice call, Dalchina! -- now running on the boss's PC. It's going to take a while because of the 36.5 GB of "stuff" in that folder. Will report back on those results when it's complete ... 15 minutes later: 30.43 GB removable/relocatable. Opted for the safer relocation to the 1 TB external HDD attached to her PC. Now moving ...



Took another 15 minutes to relocate everything. Now, WinDirStat reports that C:\Windows\Installer is down from 36.5 GB to a relatively svelte 6.1 GB. Great stuff!

Thanks Cerberus! I'll be digging in more deeply and writing about this for my Windows Admin toolbox series soon, I believe!

Everything said, this is exactly why I posted a plea for help and insight here. I knew there had to be a way to deal with this, and indeed there was. Thanks again to one and all.

Best wishes,
--Ed--

I never bother copying files to another drive personally as I always make regular image backups. I have never had a problem just deleting them anyway but that is me. Of course backing up with tool is safer.

I'll endorse the general sentiment for backups. I run file history to capture Library folders every 6 hours, and use Macrium Reflect (free) to capture nightly incrementals and weekly full/image backups. I also copy my weekly into the cloud (OneDrive, thanks to a 1+TB allocation from various promos and an Office 365 subscription) for extra redundancy. When it comes to backup, I believe you can never have too many, nor keep them in too many places.
Thanks again to everyone for all the helpful suggestions and input.
--Ed--