Need help with Win7 security update problem big-time


I have a 6 year old Win7-64 system. I’ve never really had any issues with it I couldn’t solve myself but yesterday I tried to apply 11 monthly MS updates and they all installed fine except for the monthly security roll-up update, which failed with an error code of 80073701.

Some research for that error indicated that my system thinks file(s) needed for the update are missing or corrupted so I tried renaming the SoftwareDistribution folder so it would start with a fresh one. That did not work. I then ran the MS windows update troubleshooter tool but that also failed to fix it.

I then downloaded the MS System Update Readiness Tool and ran it (which took several hours). The log it generated seems to indicate that I’m missing a catalog file ( There is then a long list of missing .mum files listed after that (over 900).

Looking at the Windows updates installed on my system, I do not see an install for KB4088875. However, a search of my registry does show keys for So something happened to that catalog file.

Do any of the Windows OS gurus here have any ideas on what I could do to fix this? If I can get that .cat file from somewhere and copy it into my catalog directory will that fix it? I also thought about uninstalling all the windows updates on my system and reinstalling them but that’s last resort stuff. I also thought about trying to do the anytime upgrade to Windows 10 to see if that would allow me to do updates again. Again, that’s more of a last resort shot at fixing it.

Here’s the first few lines of my SURT log file and the summary section following. I’d appreciate any advice anyone might have on how to get past this problem.

Checking System Update Readiness.
Binary Version 6.1.7601.22471
Package Version 26.0
2018-12-10 10:17

Checking Windows Servicing Packages

Checking Package Manifests and Catalogs
(f)	CBS Catalog Missing	0x00000002	servicing\Packages\		

Checking Package Watchlist

Checking Component Watchlist

Checking Packages
(f)	CBS MUM Missing	0x00000002	servicing\Packages\Package_1000_for_KB4088875~31bf3856ad364e35~amd64~~		
(f)	CBS MUM Missing	0x00000002	servicing\Packages\Package_1000_for_KB4093118~31bf3856ad364e35~amd64~~		
(f)	CBS MUM Missing	0x00000002	servicing\Packages\Package_1001_for_KB4093118~31bf3856ad364e35~amd64~~		
(f)	CBS MUM Missing	0x00000002	servicing\Packages\Package_1001_for_KB4103718~31bf3856ad364e35~amd64~~		
(f)	CBS MUM Missing	0x00000002	servicing\Packages\Package_1001_for_KB4343900~31bf3856ad364e35~amd64~~		
Checking Component Store

Seconds executed: 7135
 Found 904 errors
 Fixed 2 errors
  CBS MUM Missing Total count: 903
  Fixed: CBS MUM Missing.  Total count: 2
  CBS Catalog Missing Total count: 1
  Fixed: CBS Paired File.  Total count: 2

Its time for Windows 10 my internet friend. ;)

I had a similar problem with Win 7 , maybe 3 years ago? Would just plain refuse to install security updates due to supposedly missing files. I couldn’t fix it after days of messing with it.

As of this summer Windows 10 can still be installed for free:

Installing Windows 10 right after a failed update in Windows 7 might not be the best idea…

I stayed on Windows 7, but I manually download the security-only patches instead of letting MS apply the rollup versions. Possibly what you need to update or fix is Windows Update itself. The site I read for critical Windows Update info is AskWoody. Their forum search turns up a lot of results for KB4088875 so I suspect you can find some answers there.

Unfortunately, I’ve tried all that stuff and more. It fails on the manual install of the security patches as well. using the MS System Update Tool, I managed to manually repair all 902 of the missing update files that CheckSUR identified (that took a week) and the SUR log is clean now. But it still fails to update with the same error. Some file is still missing or messed up somewhere that the MS diagnostic tools can’t identify. The CBS log is not helping find it.

After wrestling with it for weeks, I’ve decided to give up and just buy a new system to replace it.