This thread is a bit off.
Desktop Manager is available for download from the RIM web site - download v4.2 SP1.
You can transfer media between the microSD card the the PC without DM. On the BB, set the microSD to "Mass Store Mode Support" to On (go into Options / Advanced / Media card).
When you connect the BB you will be prompted to enable Mas Storage Mode - if you reply yes, then the card (BB) will appear as a hard drive on the PC and you can transfer files directly. Not via DM - that is for transferring files to the BB itself (internal memory)...