📎 AI Summary:
The thread centers on a Windows issue where, after a day working normally, several desktop/taskbar-launched apps (including common browsers and Office programs) stopped opening with no errors, and even running as admin didn’t help. The key breakthrough came from checking the Registry “Image File Execution Options” for per-EXE “Debugger” entries, which were found to redirect each affected program to CCleaner; removing those IFEO subkeys (and then uninstalling CCleaner) restored the ability to launch all programs. Overall sentiment is positive and resolved, with the original poster confirming the specific cause and fix.
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leguar

Active Member
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Jan 29, 2024
Messages
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Thread Author #1
From one day where all is function as expected, the next day some programs could not open when called.
Calling links from my Taskbar or links at my desktop, nothing happens when I try to open some programs.
No errors or msg. shows up. Cant find anything in logs.
Calling programs eg. Firefox, Chrome, Excel, Word and some other programs.
Have tried to open the programs with Admin, but to no avail.
Even tried to open the programs from the startbutton, but still to no avail.

Any hints, what can cause this strange happening ??
 

Solution
WindowsForum AI
Great work tracking it down—that explains the behavior perfectly.
What happened
  • CCleaner’s “Smart Cleaning/monitoring” can register itself as a Debugger under Image File Execution Options. That forces launches of app.exe (chrome.exe, excel.exe, etc. to be intercepted or redirected, which makes programs fail to open when the Debugger path is broken or blocked. Removing those IFEO subkeys (and then uninstalling CCleaner) clears the launch hook.
Quick clean‑up/verification
  • Check there are no leftover Debugger hooks:
    PowerShell (Run as admin):
    Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options' |
    Where-Object { (Get-ItemProperty $.PsPath -ErrorAction SilentlyContinue).Debugger...
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WindowsForum AI

WindowsForum AI

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#2

Quick checks to narrow it down​

This pattern usually means Windows’ shortcut (.lnk) association got broken, or something is blocking process launch for certain apps.
Please try these two quick tests:
1) Press Win+R, type notepad and press Enter. Does Notepad open?
2) Press Win+R and run the full path to an app, e.g.:
"C:\Program Files\Mozilla Firefox\firefox.exe"
"C:\Program Files\Google\Chrome\Application\chrome.exe"
Do they open this way?
  • If they open via full path but not from desktop/taskbar/Start: your .lnk (shortcut) association is likely broken.
  • If they do not open even via full path: something is blocking launches (policy/AV/registry), or system files are damaged.

If shortcuts are broken (lnk fix)​

1) Create a restore point (optional but recommended).
2) Open Notepad, paste the text below, save as FixLNK.reg (set Save as type to All Files), then double‑click it and accept the prompts. Sign out and back in.
Code: 
Windows Registry Editor Version 5.00 [HKEY_CLASSES_ROOT\.lnk]
@="lnkfile" [HKEY_CLASSES_ROOT\lnkfile]
@="Shortcut"
"EditFlags"=dword:00000001
"IsShortcut"="" [-HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.lnk]
Tip: After this, desktop/taskbar/Start shortcuts should launch apps again.

If apps won’t start even by full path​

Try these in order (test after each step):
1) Safe Mode: Hold Shift while clicking Restart → Troubleshoot → Advanced options → Startup Settings → Restart → press 4. If apps open in Safe Mode, a third‑party startup/AV is blocking them. Perform a clean boot and re‑enable items to find the culprit.
2) System file repair (elevated PowerShell or CMD):
sfc /scannow
DISM /Online /Cleanup-Image /RestoreHealth
3) Check for rogue “Image File Execution Options” (malware sometimes adds a Debugger to block apps):
  • Run regedit and browse to:
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    If you see subkeys like firefox.exe, chrome.exe, excel.exe, winword.exe with a value named Debugger, delete those subkeys (only those), then reboot.
    4) New test user: Settings → Accounts → Family & other users → Add someone else to this PC. Sign into the new profile and try launching the apps. If they work there, the issue is profile‑specific (we can reset associations and startup entries in your main profile).

Two quick questions​

  • Did this start right after a Windows Update or installing/uninstalling security software? If so, which and on what date?
  • What exactly happens with Win+R notepad and with running the full .exe paths above?
Reply with those results and I’ll give the next exact step based on what you see.
 

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leguar

Active Member
Joined
Jan 29, 2024
Messages
9
Thread Author #3
@ ChatGPT

This suggestion did it:

<snip>
3) Check for rogue “Image File Execution Options” (malware sometimes adds a Debugger to block apps):
  • Run regedit and browse to:
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    If you see subkeys like firefox.exe, chrome.exe, excel.exe, winword.exe with a value named Debugger, delete those subkeys (only those), then reboot.
</snip>

Every "programname.exe" had a subkey with a call to CCleaner, which I used (until now).

First I removed the subkey within Excel, closed and rebooted. Now I could open Excel.
Next I tried to remove the subkey within Chrome, closed and rebooted. Now I could open Chrome.
Next I uninstalled CCleaner, and checked the register, and all subkeys to CCleaner has disappeared.
And tested again with other programs not opening, and now all the other programs will open.
 

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WindowsForum AI

WindowsForum AI

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Robot
Joined
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Messages
114,175
#4
Great work tracking it down—that explains the behavior perfectly.
What happened
  • CCleaner’s “Smart Cleaning/monitoring” can register itself as a Debugger under Image File Execution Options. That forces launches of app.exe (chrome.exe, excel.exe, etc. to be intercepted or redirected, which makes programs fail to open when the Debugger path is broken or blocked. Removing those IFEO subkeys (and then uninstalling CCleaner) clears the launch hook.
Quick clean‑up/verification
  • Check there are no leftover Debugger hooks:
    PowerShell (Run as admin):
    Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options' |
    Where-Object { (Get-ItemProperty $.PsPath -ErrorAction SilentlyContinue).Debugger } |
    Select PSChildName, @{n='Debugger';e={(Get-ItemProperty $    .PsPath).Debugger}}
    If this returns nothing, you’re clear.
  • Optional: Task Scheduler → Task Scheduler Library → remove any CCleaner tasks if present, and Task Manager → Startup tab → ensure no CCleaner entries remain.
  • Going forward: I’d avoid registry/system “cleaners.” Windows’ built‑ins (Storage Sense, Disk Cleanup, Reset this PC) are safer and won’t hook IFEO.
If you ever reinstall CCleaner, disable all “Smart Cleaning/Monitoring” features so it doesn’t create IFEO entries again. If anything similar pops up, let me know and we’ll dig deeper.
 

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