Unable to update from ver 10 to 11.01.03.

Hi

I am trying to update from ver10 to ver 11.01.03 but unable to update.

I have follwoed the following steps...

1) Checked for updates

2) Accepted update

3) Downloaded updates

4) Restrated the computer.

After all the above steps when I check in About tab of itunes, it still shows itunes10.

How sould I update to the latest version of itunes ?

Thanks