Imported audio just plays in the first 2 minutes

(I’m using Audacity 2.0.1 on Windows 7 Ultimate x64)

Well, I’m a guitarist, and I’m trying to record some guitar parts over a mp3 backing track I have.
The problem is: When I click Import > Audio, and select the mp3 file of the backing track, it creates a track on audacity, but only with the first two minutes of the song (even though the song is 5 minutes long).
One thing that I realised, is that the track “stops” exactly when my computer screen ends. It’s like this:

When I import the track, it looks like this (you can see that my screen only shows until the second minute):

But, when I scroll left, to see the end of the track, ir goes blank:

So, that’s it. Could you help me? haha
Thanks in advance.

When making screen shots, could you resize Audacity to small size so that the screen captures fit on a forum page.
I can see the full image by right clicking and selecting “View Image”, but it’s not convenient to do so.

Does this happen with just one particular file, or do other imported files do the same?

Oh, sorry about that. Yes, it happens with every file I import.

Check in “Edit > Preferences > Directories” and ensure that the “Use RAM” option is not selected.
If it is already not selected, how much free drive space is there on your C:/ drive, and what is the total size of the C:/ drive?