Hi , There is a tip which enables UMS /MSC with Nwz-a81* (61x) support on Windows XP/(Vista). ° Open the Device Manager (Right click on 'My Computer' Icon > Properties > Hardware Tab (XP Systems) ) ° Locate The walkman drive (generally in 'Disc Drive ' Portable Devices List) in the device list ° Right-click on it, select 'Update Driver...' ° A driver wizard window will appear : ° On the 'connecting to Windows Update' prompt, Select 'no, not this time' , then click Next ° Choose "Install from a list or specific location (Advanced)", then click Next ° Verify that "Show compatible hardware" is checked ° In the list, 2 drivers will be available, "MTP Device" and "USB Mass Storage Device", select this last one to use UMS with Windows XP (vista). (To revert back to mtp mode, just repeat previous steps, and select MTP Device here.) ° On the next screen, press finish, it is done. The player will be recognized as a Removable Drive (msc). On Linux systems, this player will automatically switch to UMS/ MSC mode.