Well, I went to buddies place to convert my T10 to UMS mode using firmware updater v1.7 and his XP machine. After updating (Which required internet connection by the way - no option for manual), it prompted for device to be disconnected and then device would reset and update a few times. Upon disconnection, the T10 just went dead. After getting home, I reconnected it to my W2k system - nothing... still would not recognize the device. After attempting to re-install driver again I got message "The file 'secums.sys' on USB Mass Storage Disk is needed". !?!? So, I tried again installing driver, using an alternate driver which Windows suggested was available. This time it worked! (and this driver is quite dated - 1999!). OK - now to test the T10. All folders (Playlist, Voice, Record) were all there - in addition to a system file 'T10.sys' (a hidden file - 512 bytes long, 8192 bytes used). My question is CAN I DELETE T10.sys FILE SAFELY? This is totally strange to me - My wife's no name cheapee UMS Mp3 player has no such files on board and is completely empty ready to be loaded with Mp3 songs. Iriver - Why do you make things so complicated?!!! Can you not simply include a folder of drivers on your WMP10 cd for all XP, W2k, W98 users??? I guess you made too sweet of a deal with MR. G. from Microsoft....pretty well forcing users to own XP machines....PS: added 'Dara' folder to T10 and can now transfer .BMP files to it.