Several people seem to report issues with ADE and Windows 8 with difficulty of navigation.
I haven't seen it and don't have a direct solution. It is working fine for me (as you say it did for you originally).
As a general comment I prefer v1.7.2, but for reading experience and bug avoidance.
There are lots of bugs in ADE2.0. Try replacing ADE2.0 with the older but more reliable v1.7.2.
(You can have them both installed at once if you like.)
Version 1.7.2, it is a little difficult to find, available on Adobe site for Windows and for Mac.
The forum software is sometimes corrupting the link above. There shouldn't be a blank in 'editio ns.html'. The following redirects to the same page: http://tinyurl.com/diged172