How to convert 2gb to 4gb :
1.) Go here
2.) Download and extract the software on desktop.
3.) Open the folder.
4.) Make sure you have connected your pendrive/memory card to your PC.
5.) Open Driver increaser 2.
6.)Enter the name of your pendrive.
7.) Enter The drive letter.
You may check your pendrives Drive letter and enter it , It will ask for drive letter again , And Guess what and then You are done You have a brand new 4gb pendrive