Sandisk Extreme 16gb 45MB

I recently purchased a canon t4i camera.  I also purchased the sandisk extreme 16gb memory card. 

I have been regularly inserting the sandisk into my laptop(windows8) and all worked fine.  I recently filled it to its capacity and wanted to view the pictures but now my laptop does not recognize the SD card.  The error message states "please insert a disk into SD Card (E:).

I then inserted it back into my camera and it does not recognize the sd card there either.  How can I get this to work?  I want to at least get it to work 1 more time so I can transfer the pictures and return the Sandisk under warrenty.

Please help.

Desperate for my pictures …

APetrie

ps.  this was my attempt at backing them up… I never got the chance to

This happened today with me with the same card SanDisk Extreme 16GB 45 MB/s.

It is not recognized anymore in Windows 7 Disk Management. I can not access it or format it with any tool. GParted does not see it either.

Please help.