Windows 10 1903: Microsoft's CPU spike fix breaks search on Start menu, desktop

Microsoft has had a bad run with Windows 10 version 1903 in the past month, leaving users wondering whether it's worth installing the latest security update or to wait for yet another fix.

The September Patch Tuesday security update also fixed the Windows 10 1903 Cortana CPU issues but has broken Windows Desktop Search, according to users. 

A string of bugs have occurred over the past month since the August 13 update KB4512508 for Windows 10 1903, which broke apps written in Visual Basic 6, VBA, and VBScript for all versions of Windows 10 back to Windows 7. 

SEE: 20 pro tips to make Windows 10 work the way you want (free PDF)    

A week later Microsoft patched this issue for all versions of Windows except Windows 10 1903, which finally got fixed in a separate update, KB4512941, on August 30.   

But KB4512941 also spawned reports from 1903 users that the Cortana process SearchUI.exe was causing severe CPU spikes, which Microsoft confirmed last week, promising a fix that arrived in the September Patch Tuesday update KB4515384 this week. 

As Microsoft noted on Tuesday, the high CPU usage from SearchUi.exe "issue only occurs on devices that have disabled searching the web using Windows Desktop Search". 

But whatever adjustments Microsoft made have caused more problems with Windows Desktop Search and the Start menu. The issue only affects Windows 10 1903. 

"Microsoft has received reports that some users are having issues related to the Startmenu and Windows Desktop Search," Microsoft notes. 

The company is "presently investigating and will provide an update when more information is available".

Windows 10 1903 users on Reddit have complained that after installing the Patch Tuesday update, the Start Menu "results in a blank window again". 

Reddit users appear to be losing patience with Microsoft's ongoing Windows 10 fumbles. 

"Typical Microsoft, fixes the CPU usage by completely breaking search so it can't even be used," wrote another Windows 10 user. 

READ MORE: Microsoft is starting to auto-update Windows 10 Home, Pro users on 1803 or older to 1903

Microsoft is also drawing criticism on the Windows 10 Feedback Hub, where a user is recommending others against installing the security update, as per MSPoweruser. 

"KB4515384 should address an issue that causes high CPU usage from SearchUI.exe for a small number of users. But this update again introduces the same problem as the previous update. Part of the problem is a high CPU usage (~30%) and a totally broken search function. Currently, I see no other option than to blacklist this update also to prevent update to reinstall it again and again." 

Which brings users of Windows 10 1903 – the latest version of Windows 10 – back to the same predicament they were in a month ago. Should they install a security update with fixes for 17 critical flaws or wait for the next update that may or may not address bugs that break key Windows 10 features?  

At least one Windows watcher, Woody Leonhard, was rightly skeptical on Tuesday when noting that KB4515384 included an "apparent fix for the SearchUI.exe" bug.

More on Microsoft's Windows 10 updates

• Microsoft: We've fixed Windows 10 1903's Cortana CPU spike bug
• Windows 10 1903: Buggy update slows PCs, breaks Desktop Search, says 
• Windows 10 CPU spikes? 1903 update brings fixes but also high usage issues
• Windows 10: We're now gearing up for 1909 with new throttled release, says Microsoft
• Microsoft: These Windows 10 updates fix broken Visual Basic apps but not for 1903
• Microsoft warns Windows 10 admins: No more patches for 1703 after October 9
• No more buggy Windows 10 updates? Microsoft makes it easier to flag early flaws
  
• Windows 10 recovery: Microsoft borrows Apple's Mac cloud reinstall feature
  
• Microsoft releases two new Windows 10 19H2 test builds
• A new look for Windows 10 Start menu: Live Tiles ditched in leaked preview build
• Windows 10 19H2: If you're on 1903, expect 'far faster' update, says Microsoft
• Microsoft starts testing Windows 10 19H2 in the Slow Ring
• Windows 10 updates: We're now using AI to push 1803 users to 1903, says Microsoft
• Windows 10 yields more secrets: Microsoft plan to split OS from shell takes shape
• How to delete the Windows 10 paging file on every shut-down TechRepublic
• Test Microsoft's Chrome-like Edge browser for Windows 10 CNET