Your origanal post said you installed ovil suite, not pc suite. Which program do you have? I originally installed ovi suite, which is NOT compatible with the N900. I then installed pc suite, and have tethered many times with no problem both via micro usb and blutooth. Make sure you have the newest pc suite installed, connect your N900, and after it installs the drivers, fire up your pc suite. On the top right will have a 2-way arrow icon and says connect to the internet. Set up a new connection by selecting the appropriate carrier (t-mobile USA in my case) and in a few seconds you should be connected with no problems.