Applications getting stuck during installation

There have been several applications which I have tried to install where the installer just got stuck. This includes Windows Live Messenger which dies when using the defaults (installs more or less everything additional). Adobe Flash CS3 installer also froze my PC a few times and the application dies on startup. Dreamweaver doesn't close down properly, it always remains running as a process. Unless that process is killed, it will not become visible again. Windows also gets stuck during shutdown for some odd reason after already closing all running applications before doing the shutdown.

Windows/Live/MSN Messenger issues

I have tried various versions rebrandings and incarnations over the years (since 1998) and always found mostly severe login problems as well as installation issues. To top it all off, logging into Hotmail/Windows Live Mail also had and still has issues.

The latest Live Messenger has got major login problems after upgrading to the latest version. To make things even more exciting, the apparent solution is to clear out its cache in two locations which did not help me at all. An uninstall is not possible either because it is not listed in Add/Remove Programs in Control Panel.