Try to use the old PC Suite. Download one from Nokia Europe and search for phone compatible with E90. (This is the one that I am using),and do not use the OVI Suites yet (New version of pc suite). See if this will solves your problem.

Also, try to see if you can use other machine to test. I am using XP SP3, and PC Suites. So I know it works.

One more thing: Please make sure you connect directly to the USB port (do not use USB hub).

I just tested on a different machine (also windows) with the same pc suite version (actually the very same file) and it worked there. The problem must be in my windows. I will reinstall later and post the result of that here.

tirtawn - you have made me a very happy camper indeed. I have been battling with how to get the freakin' thing to synch via usb for months now. Finally had to knuckle down and find it when my new laptop was delivered without bluetooth. Thanks a mill. For anyone trying to use the USB cable to synchronise via PC Suite and getting the "mass storage mode" error, the fix is exactly this - plug the usb cable directly into a usb port and not a usb hub. Thanks again.

I am having the same problem, still no solution so far

guys! just saw this topic.. you have two options, 1. go to c\windows\inf\wpdmtp.inf.. (well if you see it, means old windows) then go to www.infdump.com download the new wpdmtp.inf and replace the older one, (its still doesnt work? it means windows version is not support your modem theres no way to install in those windows) you have the the last option. reinstall your windows with newer xp version, such as xp sp2 2002 is one of them, after it dont install any programs first, but install PC 1st, (bcs some program can change inf contents and state of your windows like avira etc ) your modem will be 100% installed, after it you freely installed your antivirus etc. hope it will help. sorry for bad english