The new Windows Live installer is truly horrible. It took me almost 30 minutes to install just Messenger and even then i didn't have an option to not install Sign-in Assistant. I know more people hate this bundled installer, so i extracted just the new Live Messenger installer in a few languages so you don't have to go trough 30 minutes of pain for a Messenger update that doesn't seem to have anything new anyway.
These files will install Live Messenger "2008" v8.5.1288.816 WITHOUT Sign-in Assistant or the buggy Windows Live installer:
EDIT: MOAR working links added.
Separate installers in various languages...
Windows Live_Messenger 2008 8.5.1288.816:
http://random.menthix.net/windows_live/Windows_Li...n-us_(English).msi
http://random.menthix.net/windows_live/Windows_Li...ar-xa_(Arabic).msi
http://random.menthix.net/windows_live/Windows_Li...bg_(Bulgarian).msi
http://random.menthix.net/windows_live/Windows_Li...s-es_(Spanish).msi
http://random.menthix.net/windows_live/Windows_Li...-ee_(Estonian).msi
http://random.menthix.net/windows_live/Windows_Li...t-it_(Italian).msi
http://random.menthix.net/windows_live/Windows_Li..._nl-nl_(Dutch).msi
Windows Live Sign-in Assistant:
http://random.menthix.net/windows_live/Windows_Li...n-us_(English).msi
Windows Live Mail 12.0.1365:
http://random.menthix.net/windows_live/Windows_Li...n-us_(English).msi
http://random.menthix.net/windows_live/Windows_Li..._nl-nl_(Dutch).msi
Windows Live Writer 12.0.1277.816:
http://random.menthix.net/windows_live/Windows_Li...n-us_(English).msi
http://random.menthix.net/windows_live/Windows_Li..._nl-nl_(Dutch).msi
Windows Live Photo Gallery 12.0.1193.81:
http://random.menthix.net/windows_live/Windows_Li...n-us_(English).msi
http://random.menthix.net/windows_live/Windows_Li..._nl-nl_(Dutch).msi
Windows Live OneCare Family Safety 1.8.4420.0:
http://random.menthix.net/windows_live/Windows_Li...n-us_(English).msi
http://random.menthix.net/windows_live/Windows_Li..._nl-nl_(Dutch).msi
Windows Live Toolbar 03.01.0000.0130:
http://random.menthix.net/windows_live/Windows_Li...n-us_(English).msi
http://random.menthix.net/windows_live/Windows_Li..._nl-nl_(Dutch).msi
The installers will do their job automatically without showing anything on screen, after they finished Messenger should be installed and accessible from the startmenu.
How to extract separate (clean) installers yourself:
These steps will work for all the Live products bundled in the installer.
1) Set your preferred browser language to the language you want your Live products in. Don't worry, just go to step 2 directly if you don't understand this.
2) Visit
http://get.live.com/wl/all to download the Windows Live installer in your own language, or if your language isn't available yet, get the English version at
http://get.live.com/en-us/WL/config_all. Make sure you only select the parts you want before you start the download.
3) Run the WLinstaller.exe you just downloaded and let it download all the products you want. Unfortunately installation will automatically start after that, just ignore that and let it go for now.
4) Press Start > Run... > and open "C:\WINDOWS\system32\config\systemprofile\Local Settings\Application Data\WindowsLiveInstaller\MsiSources".
5) In the folder you just opened you should see Windows Installer Packages (.msi files) if the installer finished downloading successful. If there are multiple of these files you can check which product each file is by right-clicking them > Properties > Summery > Subject.
6) Copy the .msi files of the products you want to a safe place (for example your Desktop). Rename the file to something more famaliar if you like.
7) Go to Start > Control Panel > Add or Remove Programs. You can now remove the crap the Live Installer forced you to install like "Windows Live Sign-in Assistant" and "Windows Live Installer".
8) Use the .msi file you copied in step 6 to do clean installs. These MSI packages install without showing anything on screen, after they finished you should find the working product in your startmenu, if not, reboot and try again.
9) Share the MSI installer you just extracted with people who have problems with the full Windows Live Installer, or people who just don't want the extra crap.