1. Make a Backup of all the content on your Micro SD card and save it some place safe on your Computer, for example create a Folder on the desktop and put everything in the folder that you have on your Micro SD Card.

2. Download and install SD Formatter 3.1

3 Open SD Formatter 3.1 from the start menu or by the new fresh desktop shortcut.

4. When SD Formatter 3.1 opens you will be shown this window:

5. Now We are going to Press the "Options" Button and will be shown this brand new Window!

6. Now Select as show in the image "Format Type: FULL (overwrite)" and "Format Size Adjustment: ON" and then press the OK Button!

7. Now before we do anything else, DID YOU REMEMBER TO DO A BACKUP OF YOUR MICRO SD CARD CONTENT? If you did now let's go to number 8.

8. Now you have to press the scary looking "Format" button as shown in image below, when you press it will take some time before it's done, do not remove the micro sd card during the format progress.

9. Now when the format is complete, remember the backup you did? Put everything back on your micro SD card, and while you are at it, check if your R4wood/Acekard/DSTWO or whatever flashcart have a new update, I suggest you to use Ron975's awesome FlashcartHelper to download the latest firmware for your flashcart.

10. Phew everything is back were it should be (hopefully) and you maybe even got yourself a better update for your Flashcart. Now this guide have solved problem with slow micro SD card in maybe 90% of the cases.