i am using windows 7 home premium 64-bit and even tried windows xp compatibility mode. the first time i tried to install it..gave some error message but i did not write it down.
If you downloaded and installed the Sansa Firmware Updater before, you do not need to download it again.
(Cowon is a notable example.) In addition, the players now support the most advanced Audible AAX format (type 4), and they include enhanced control over audiobooks and podcasts.
STEP 1 - Download the Sansa m200 Firmware Updater file and save it to your desktop. Double-click the downloaded file (sdmx3-iv001.exe).
Slide the HOLD switch to the lock position (orange color will show).
STEP 4 - Plug the Sansa Express player to the PC in recovery class mode 1.