Can't acces external SD from my PC

HI r/android, i am relatively new to this kind of phone so i had a quick question to a problem i have been having.

My Phone: Samsung galaxy s2 skyrocket version 2.3.6

So I have my files (music, tv shows, etc) stored on the extaral sd on my droid ( i believe this is calld the k disk, as this is how it appeared when i plugged my phone into my computer) Anyways, when i did plug my phone in, and connected it up when i hit the button, two different windows would open, one for k disk and one for j disk. I hit "open folder to view files" and put my stuff on there. My problem is that the last time i plugged in my phone, the k disk did not appear! I have tried mounting/unmounting the sd card and connecting/disconnecting the phone to my computer multiple times, but to no avail. So i have 2 main questions:

1.) Is this the best way to store my media on my phone?

2.) How do i access the K disk (or exteral sd, i believe) from my computer, now that it has started diappearing?

Thanks so much for reading this and as i am new please correct any false assumptions i make. thanks!