how do I uninstall mobilme

You need to do a better job of explaining your issue. Mobileme is a web based service, not an application installed on your computer. Because it's a web based service you cannot uninstall it.

Are you talking about the MobileMe gallery or iDisk apps on your iOS device? You can remove those in the apps tab in iTunes when the device is attached.

Otherwise, as rkaufmann said above, there is nothing to uninstall on your Mac or PC. It's a cloud service which is being discontinued in summer 2012.

After some searching, I have figured out how to uninstall MobileMe, when it is not listed on the Control Panel. On Windows 7 (and perhaps Vista and XP), there is a hidden directory C:\ProgramData. Go to C:\ProgramData\Apple\Installer Cache. There will be a directory for MobileMe for whichever version is installed as MobileMe.x.x.x. Under that directory, there is an uninstaller. Run that and MobileMe is gone!