WMP12 won't allow me to add music to my library (no dialogue)

Hi

When I purchased Windows 7 I purchased the N version which does NOT come
with WMP12 or any other media features. As a result I had to add WMP and
the other media features using Microsoft's Media Features Pack. Somehow
or other I initially managed to add music to my WMP library but for some
time now I've not been able to add music. In fact under Manage Libraries
I can only add Recorded TV - I can't add Music, Video or Pictures.

Absolutely nothing happens when I click on Organize|Manage
Libraries|Music/Video/Pictures, no dialogue box comes up at all on any
of these options and I suspect I may be missing either a .dll file or
some registry entries or both. I've done a search on the forum but so
far I've not found anything relating to this problem or anything close.

So my question is: does anyone have a possible solution to this or any
suggestions (other than reinstalling Win7 that is). Any help would be
most appreciated. Thanks.

Incidentally, what part do libraries play in this.

Since initially writing this message I've done some further poking
around but still haven't come up with a solution. So HELP!!!

Tracey