How To Reformat ANY SD Card!!!!
 

** WARNING THIS IS A LAST RESORT THAT WILL WIPE CARD CLEAN AND IF IT CANT BE WIPED IT WILL SHOW THAT THE CARD IS DAMAGED AND NEEDS TO BE REPLACED. MOST CARD HAVE AT LEAST A 1 YEAR WARRANTY ON THEM CHECK THAT OUT AS WELL. SO BE READY FOR THE CARD TO BE WIPED IF ITS NOT DAMAGED AND YOU USE THIS PROCESS**

I´ve had trouble with my Sandisc microSD card (8gig), corrupted files / I/O Error / Missing Files, this will check if the card is damaged or not and includes several tips on using memory cards, it´s alittle bit long to read, but may be worth it, so here goes:
Some hints of using SD memory cards
1. Do NOT remove the memory card while it is operating, otherwise it may be
damaged.
2. Do NOT turn off the device, while the operation of writing /reading is
not completed.
3. When the battery power of system is low, do not write to the memory card to prevent loss of data.
4. Make sure the device (card reader/phone/camera/pda/camcorder) has finished reading/writing to the card before you take another shot/turn it off or the data will be corrupt/lost and the card will be damaged. You can tell by the device indicator light where it flashes when it is reading and writing to the card. Wait until the indicator light is off and stops flashing before you take another shot/turn the device off or remove the card/drive.

Before you continue, please make sure you have a reader that can read and write to 8GB card properly. I recommend using it in external USB 2.0 reader.
If you do not have such reader, then connect the device (gps/camera/pda/camcorder) to the computer with USB cable and the card inserted.

Please try the following troubleshooting guide first and see if it can solve the problem. Try one step at a time. If one works, then you can stop trying. You don't need to try all of them.
The following guide will erase all the data on the drive/card. So make sure you backup your data first before you try the steps below:

1. First, remove the card/drive from your computer.
Install low level format tool below to your computer.

You should see a new icon called "Hard Disk Low Level Format Tool".
a. Insert the card/drive and run the program.
IMPORTANT!!! MAKE SURE YOU SELECT THE CORRECT DISK OR YOUR COMPUTER MAY NOT START LATER!!!
It should shows as BUS: USB. Select the BUS: USB. Also check the size and make sure.
If you don't see BUS: USB, that means the card is unreadable and need to be replaced. In this case, please STOP here and close the program and DO NOT continue below.
b. Then click Continue->Low Level Format->Format this Device.
c. Wait for a few minutes until it finish successfully with a message of asking you to partition and format it. (if you see formatting error, you can stop the formatting and the card needs to be replaced.)
Once complete Flash the Card:
Either put the card back to your device (camera/phone/pda/camcorder) and then use the format utility to format the card if you have an internal reformatter.
Or Just keep phone hooked up to CPU and use the Reformatter provided below and find the correct Card.
**The Programs must be installed onto CPU not Phone.**
Hope This Helps everyone out,
**Please let me know the results**