I have a win 7 64 bit system (ASUS). There are no trojans or other problems and there is no kill-bit in the registry. My browser is Firefox 8. I uninstalled Version 10, hoping that would help.
I download the software OK. When it executes, it hangs there. I can see it in the Task Manager. Apparently it is waiting for a response from me; however, I can't see the request box. Therefore I can't install.
Download the installer from http://forums.adobe.com/thread/909550
When you see this panel
make sure that the checkbox "I have read and agree..." is checked before you click the INSTALL button.
If this is not where you are hanging, please post a screenshot of your situation.