Some programs don’t show in the taskbar

This is a strange issue that I’m puzzled with. When I start a Firefox for example, it would run in the background, but the main program window does not show up, same thing with K-Meleon browser. IE 8 runs fine and so does Opera. Something with Mozilla based browsers. Reinstalling browsers did not solve the issue, neither did the restarting the Explorer.exe shell. I’m running Win. XP SP3. Any thoughts on this, what could I be missing?

 

May relate to malware?

Try a quick scan with an updated Malwarebytes.

 

I did scans with Hitman Pro and Malwarebyts, nothing was found. Before that, I installed Norton Antivirus 2011 to trial it, and that's when it all started. So I proceeded to uninstall it clean, but it did not resolve anything. That's the only change I did to my computer.

 

Could it be that some of the DLL's are not registered?

 

Do you have any restore points to before installing Nortons? If so then maybe try a restore to then.

 

No restore points to revert back to. I suspect something is missing or corrupted that requires Mozilla based browsers to show in the taskbar. Have to figure this one out...

 

Try running Process Monitor, you should be able to see where things are failing.

 

I'm not sure what to look for when using Process Monitor...
Like I said before, the browser runs in the background but the main window does not open in taskbar.

 

process explorer has an option to bring to front if you right click on the running process and click on properties.

if you use that option it may give more information.

 

I tried that, and the "window" option is grayed out.

 

I managed to resolve the issue by uninstalling Avast AV and cleaning out traces with their removal tool. Thanks to all who tried to help!