Paul said:
Javascript is not the same thing as Java. Uninstalling
Java will have absolutely no effect on Javascript or any
file with the .js extension.
Paul
I didn't have any Windows 7 files handy, so I grabbed ieframe.dll from
my Win8 partition. Some DLL files, they contain mainly resources,
and they end up being a "miniature file system".
I used resedit from resedit.net to access ieframe.dll.
(I dragged and dropped it, onto the open resedit window.)
In the "HTML" section of the resources, I can find preview.js.
http://img694.imageshack.us/img694/7138/ieframe.gif
What I can't figure out, is what it's complaining about :-(
If I go to the top of that resource file, it says
var g_nFramesetLayout = 0;
which means that variable is defined OK. It has a valid value,
due to being declared at the top of the code.
This result, won't necessarily align with the OPs files. The OP
should give it a try, locate ieframe.dll, locate the preview.js
resource, move to line 1536, and see what gives. The ieframe.dll
could vary from release to release of IE. I just tried this,
because I've never used a resource editor before
(To edit preview.js, I selected all the text in the right hand
pane of resedit, and pasted it into a blank notepad window. Then,
used the GOTO function to find line 1536.)
Some browsers have an error console, which is another place to
view errors and look for "hints" as to how things ran off the rails.
Paul