I am on a windows 7 computer. I have been trying to install world of warcraft: burning crusade so i can continue on and install all the other expansions but everytime it gets to 77% installed it stops and says that there is a problem and the blizzard installer has stopped working. I have the original world of warcraft installed and I even have two months of playtime on my account. I have run as administrator and I have taken out the disk and I have no idea what to do. Can someone please help?