Check Settings:1. Go to Settings >> Advanced Options >> Media Card
2. Check the following settings (if they are not listed this way, then change to reflect the following:
a) Media Card Support: On
b] Mass Storage Mode Support: On
c) Auto Enable Mass Storage: Yes
3. Save the settings and exit
To add media to the microSD card you have two options:Option One1. Make sure desktop manager is not open
2. Plug the device into the PC using the usb cord
3. A pop up box will open, select Open folder to view files using Windows Explorer
4. Minimize this window (click the - in the upper right hand corner)
5. Open another instance of Windows Explorer
a) Start Menu >> Windows Explorer
6. Navigate to the folder where the file(s) you want to transfer are located
7. Right mouse click on the file(s) and select Copy
8. Open the minimized window (from step 4 above)
9. Navigate to the folder where you want to save the file
10. Right mouse click and select paste
11. The file is now on the microSD card
Option Two1. Open and start Desktop Manager
2. Select Media Manager
3. A dual window box will open with PC files listed on the left hand side, and Device files listed on the right hand side
4. Select a file to transfer from the PC files (left side) and click the arrow to transfer the file to the Device (right side)

drag and drop or copy and paste

Holy crap now that's a long process!!!

1.Plug your bb to your comp
2.Open folder
3.Copy Paste

Done

Pearl 8100: On the Mac.
Have the latest Desktop Manager, and the Device Software. Possibly the driver as well if the computer does not recognize the SD as a mass storage.
Plug in the computer. The phone will as if you want to allow use of mass storage. Click yes and an external driver icon should appear. Open it, and the "Blackberry" folder should contain videos, pictures, ringtones etc...