Thanks for using the answers forum! I'm sorry that you're experiencing this issue with your guide on your Windows 7 64 bit machine. I would need to know which browser you are using to narrow down the possible causes here. However, one thing I would suggest is to make sure that you are using a 32 bit browser, as there definitely could be a compatibility issue with a 64 bit browser. If it's IE, you'll want to go into your start menu>all programs and open the 32 bit version of IE and not the 64 bit one.
Here is a link from our support site which lists all compatible systems and browsers:
Hope this helps!
The Sling Moderation Team