How does Ubuntu communicate with the Win 7 installation?

Really interesting techs!  Thank you for posting.  I may have more questions about this.

Rindi, yes I installed ubuntu on the same hdd so I get a boot menu choice when I start the pc.

So as I read these posts my understanding is that even though ubuntu can get my music, since it doesnt read .xxx file extensions, it cannot be attacked by malware.  But arent music files an extension type file, too?  If ubuntu can read the music files, why cant it read the rest of the data on my Win 7 install?

It can read all files, but it doesn't necessarily know what to do with all of them as windows uses extensions in file-names that Linux doesn't use. Even if the extensions are the same, code written for Windows won't run on Linux. Also, most malware comes as executable files, and in Windows those are files with the "exe" extensions. Those executables have to be run in most cases for the malware to run and load into the memory of the PC and start it's actions. As Linux doesn't know what to do with those files it can't start the malware (actually, with "wine", which is a Windows emulator that runs on 'nix platforms, you can start many of those files under Linux, provided wine is installed, but because Linux works differently the malware will usually not be able to do any harm to the OS, and apart from that software that runs using wine runs in a something similar to a "sandbox", so the rest of the OS is safe).

Music files usually are just music files, and even if malware is hidden inside it, that malware would have to be designed to attack the OS it runs on, and currently most of those  criminals that program those bugs don't bother, as Linux isn't yet that widely used as desktop OS, and it would make the programming much more difficult and time consuming.