Firefox IsThreadDesktopComposited Error

This evening I got the the following Windows XP error message on starting Firefox immediately after upgrading it from version 3.0 to 3.6. 

The procedure entry point IsThreadDesktopComposited could not be located in the dynamic link library USER32.dll

I had just finished upgrading several other software packages (Notepad++ and OpenOffice amongst them) and I assumed that one of these had done something to upset Firefox.

A search on the web revealed several blog posts which suggested that this problem could be fixed by renaming or deleting the file dwmapi.dll from the directory C:\Windows\system32.  Dwmapi.dll is only required on Windows Vista (and presumably later), and should not be present on Windows XP.

On looking, I found that there was no dwmapi.dll in the C:\Windows\system32 directory, but there was one in the C:\Windows\system directory so I renamed that to dwmapi.dll.disabled.  However, whenever I tried to rename this file through Windows Explorer, it would revert to its original name after a few seconds (presumably Windows trying to prevent malicious or accidental damage to system files?).  So I had to go into the command line to rename it permanently: click Start, click Run..., enter cmd, click OK, then enter

cd C:\windows\system

rename dwmapi.dll dwmapi.dll.disabled

This fixed the problem and Firefox now starts up correctly.

I have not identified the software package that installed the unnecessary dwmapi.dll.

Microsoft Stealth Add-on Introduces Vulnerability to Firefox

Back in August I mentioned that if you installed Microsoft .NET Framework 3.5 then a .NET Framework Assistant Firefox add-on was silently installed as well.  At the time I thought it rather dubious that Microsoft should think it OK to install stuff into a rival's browser without any indication that this was happening.  Well, it looks as if those doubts were not unreasonable.  This afternoon I got the following pop-up message from Firefox:

It turns out that the Microsoft .NET Framework Assistant introduces a vulnerabilty into Firefox, and the Mozilla team have decided to disable it.  For more details see here and here.

A Norton Internet Security Problem and its Solution

A week or so ago I noticed that Norton Internet Security (NIS) was occasionally crashing.  What would happen was that the yellow icon in the system tray would disappear while I was busy with something else.  When I noticed it was missing, I would try to restart it manually by clicking Start > Programs > Norton Internet Security > Norton Internet Security but this would always fail: sometimes I would get an error message, sometimes I would get a message suggesting that it thought I was a beta tester for NIS, but mostly the cursor would go busy for a few seconds and nothing would happen.  Restarting the computer would clear the problem but it usually came back again after a few 10s of minutes or an hour or so. 

My first thought was I had a virus which was sabotaging NIS.  However, the problem seemed to have started following a LiveUpdate to NIS about a week or two ago.  I remember this update because it was just after I had got back from a holiday and because it had required a system restart (which is unusual for NIS LiveUpdates).  Following this update the version number of NIS was 16.7.2.10 (to see the version number go to the main NIS screen and click Help & Support > About). I looked in the system event log and it contained entries which seemed to be records of NIS crashing:

Event Type: Error

Source: Service Control Manager

Description: The Norton Internet Security service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 120000 milliseconds: Restart the service.

I did a search on Google and came across this message on Norton community message board which pointed to an official patch for what seemed to be a very similar problem to the one I was experiencing.  I downloaded the file KB20090821103237EN.exe, as indicated, and ran it. After restarting the computer NIS started correctly and I have had no problems since then.  That was yesterday.  The system has been running for at least 6 hours in total.  It looks good.

Microsoft silently installs a Firefox Add-on

I just noticed that I have a Firefox add-on installed that I have no recollection of ever installing.  This is the Microsoft .NET Framework Assistant and it appears to have been installed back in February 2009 as a part of .NET Framework version 3.5 Service Pack 1.

When I first saw this add-on, I was a little worried, and my first reaction was to attempt to disable or uninstall it.  However the "Disable" and "Uninstall" buttons were greyed-out.  Needless to say, this has been portrayed in a rather sinister light out on the web. For example, see here.  Also, note that someone has added the tags "backdoor" and "malware" to the page at MSDN that describes this add-on. However, Microsoft insider, Brad Adams says here that the greying-out was down to an oversight by the .Net Framework team:

We added this support at the machine level in order to enable the feature for all users on the machine.Seems reasonable right? Well, turns out that enabling this functionality at the machine level, rather than at the user level means that the "Uninstall" button is grayed out in the Firefox Add-ons menu because standard users are not permitted to uninstall machine-level components.

The good news is that the latest update to the .Net Framework, which was installed on my machine this morning, re-enables the "Disable" and "Uninstall" buttons on the .NET Framework Assistant add-on, so you can now disable or remove it if you wish.

However, it still remains rather worrying that Microsoft should think it OK to silently install stuff into a rival company's browser, when that stuff could adversely affect the operation of that rival company's browser.

Ubuntu 9.04 Home Directories Readable by All

Yesterday I was surprised to discover that, in my latest Ubuntu 9.04 system, each user's home directory was readable to all other users (ie: permissions "drwxr-xr-x"). I seem to remember that this was not so in Ubuntu 8.10 and earlier, so I can only assume that this is a result of the latest upgrade. Whether it was intentional or not, it is not what I want, so I fixed it by starting up a terminal console and entering:

sudo chmod o-rwx /home/*

Each user home directory now has permissions "drwxr-x---" and is only readable by that user.

[Edited 2012-11-15 to correct permissions.]