How to Merge Two Hard Disk Partition into One?

Need Turn Two Partitions into a Bigger One?

Situation 1: Hello! Is it possible to merge two local disk partitions together? Recently, my Samsung laptop C partition is nearly out of space and the other partition is nearly empty. What am I supposed to do for turning these two partitions into one and also delete nothing inside? 

External Hard Drive Doesn’t Show Up on Computer

Attached USB Hard Disk Doesn’t Appear in "My Computer"?

Problem1: Hello! This morning, I plunged my 560GB WD external hard drive to my laptop as usual and wondered to upload some newly transferred videos to my computer partitions. However, this hard drive did not appear in "My Computer" as before. What am I supposed to now?

Lost Memory Card Space Recovery

Computer Does Not Shows all Memory Card Space?

Situation1: Hey, I have tried to use a 16GB SD card on a Mac computer and finally failed. So, I put it back to my Samsung mobile phone and find there is no any response. It just seems it even is not mounted there. What’s worse, when I insert it to my Windows laptop, the computer even can only recognize 40MB of this memory card space, not even the most of the card space. Is there any idea for me to fix this?