Hi cgme, several Avast users are reporting similar problems.

One possible workaround is to move Firefox to a different folder, but this won't help with your Office programs. I wish I could tell you what is going on on your system, but ???

Earlier Threads

• https://support.mozilla.org/questions/1290476
• https://support.mozilla.org/questions/1290490
• https://support.mozilla.org/questions/1290528 *
• https://support.mozilla.org/questions/1290513

Program Move Workaround

The user in that third thread reported that moving the contents of:

C:\Program Files\Mozilla Firefox

to

C:\Program Files (x86)\Mozilla Firefox

allowed Firefox to run. The user in the second thread reported that worked for them. I don't know why that would make a difference.

That helped with FF! Thank you!

Chris

FireFox working just fine until about 1500 US CDT on 9 June. It is a 64-bit Win 7 Toshiba laptop. I run Kaspersky Total Security, not AVAST. Uninstalled and reinstalled FF several times. It always installs to Program Files not Program Files (x86). Navigating to Firefox.exe and using right click, run as Adminmistrator results in same pop up dialog box as double-clicking the executable file.

I noticed that at about 1500 on 9 June, AVG/PC TuneUp did an update on its own. I only allow that for antivirus definitions, so I uninstalled AVG/PC TuneUp. Uninstalled and reinstalled FF. SAME PROBLEM.

Ran the malware scans...nothing found. Copied the entire Mozilla Firefox directory to the Program Files (x86). Firefox is now running. Logged into sync so FF looks pretty much normal.

Does not make sense that copying should work. I would have thought that the registry would balk at me manually changing the program location.

If you get a "Windows cannot find.." alert then this is a problem with Avast making changes to some registry keys.

• https://answers.microsoft.com/en-us/msoffice/forum/all/windows-cannot-find-cprogram-filesmicrosoft/963fdedb-71d9-4f2e-b8c2-561b8767b012
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options => Debugger

See also: /questions/1290490 Windows Cannot Find Firefox.exe

1. Open: run (Windows key + r)
2. Type: regedit
3. Navigate/Search to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Option
4. Delete the (Debugger) folders of apps that do not work

I'm not running AVAST. Been running Kaspersky for at least 10 years. I hadn't checked to see if other files or file types were affected. I prefer web access for my emails, so my priority has been to get FireFox up and running "normally". After posting the above message, I decided to do some desktop cleanup. Tried to open several PDF files, they all generated the Windows cannot find... message. I checked a couple of MS office files (both by starting the app and by double-clicking the file)--they opened just fine. So the problem is now with my PDF files. I believe I read another post that experienced that problem as well.

Did you check the above mentioned Windows Registry key in case this is a similar issue ?

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options => Debugger

Hi RJT97355, AVG and Avast might be offering the same products under different names in recent years.

In Avast Cleanup, the issue seems to be related to its Sleep Mode feature. They've posted a link to a fix in this support thread: https://forum.avast.com/index.php?topic=234795.0 (update announcement: https://forum.avast.com/index.php?topic=234798.0)

Based on a brief search, AVG PC Tuneup seems to have a similar feature under Speedup > Background Programs (or similar). But whether theirs also went nuts yesterday, I have no idea.

Looked at the registry. Acrobat reader had a debugger line entry pointing to AVG/PC TuneUp. I deleted just that line from the registry. PDFs are now opening. Luckily my husband does not have administrator privilege on his computer--so maybe I can uninstall PC TuneUp from there before he gets the updated version. This is why I normally require apps to have permission before updating...that way I know what recent changes might have caused problems.

Thanks all for help. If I ever knew AVG and AVAST were "related", I have forgotten it.