I had this problem also after installing the leaked version, after deleting the windows live folder, and the one in the program data folder (and yes, i had to restart) it installed perfectly
RE: Official Windows Live Messenger 8.5 Beta - Released!
it doesn't... you just can do that the plus get loaded with a trick.. but the features aren't all compatible... wait for the new release of plus... that will be soon... and FULL COMPATIBLE dude... !!!
@warmth - Beta Testing a life!
Official Nokia (former Ovi) Suite Beta Tester | Nokia Beta Labs Contributor of the month (June, 2011)