I use PC suite mode with windows 7, I never use Mass Storage as for some reason Win7 refuses to mount the memory card along with the n900 internal storage partition. If you use PC mode the N900 will appear in 'My Computer' if using windows, from here you can transfer whatever you like onto either the internal memory of the N900 or to the memory card. Alternatively you may also be able to use OVI suite as the N900 in finally compatible.