Looking for software to create an exact copy of the memory card
The best tool for dumping partitions and devices is a unix tool called dd, which is also available with almost any Linux distribution, like Ubuntu.

If you're running windows then you might want to try dd's counterpart for Windows - WinDD.

It's usually:

dd if=[source_inputfile] of=[sink_outputfile]

Warning!

These tool can do harm to your drives if used incorrectly (if you mix up data source and sink, the source will be overwritten). A quote from Wikipedia:


  It is jokingly said that dd stands for "disk destroyer", "data destroyer", "death and destruction", or "delete data", since when used for low-level operations on hard disks, a small mistake, such as reversing the if and of (input and output) parameters, could result in the loss of some or all data on a disk.


So please, be cautious.