SOLUTION: when updating to Visual Studio 2008 SP1 is half-done

When upgrading to the newly released Visual Studio SP1 you have to make sure the software gets actually installed. In other words, the lower progress bar (as shown) should go all the way to 100%. I say this because at some point during the upgrading process you get a message (I got it actually twice) asking you to reboot your system and then whether you ignore or continue the result is the same: the upgrade is NOT installed. When you try to run the program again, it runs as if nothing has happened and at some point you find out that (this was my case) you have to stop the "Machine Debug Manager (MDM)" service, AND the Windows Sidebar (apparently an important cog in the Vista wheel). After doing that I was able to to finally see the dialog box with the message "the software udpated has been installed successfully." Don't forget to take a look at, and save in another location, the installation log, an HTML file with very useful information called
%HOMEDRIVE%%HOMEPATH%\AppData\Local\Temp\Microsoft Visual Studio 2008 SP1_20080812_135937998.html (HOMEDRIVE is usually C:\ and HOMEPATH is the name of the currently logged user. To find out run Explorer using WinKey + E, and look up the first item on top, beneath Desktop).