Default Edit Voicemail - Orange homescreen

Hi there,

I changed providers and need to know how to change the voicemail number on the orange homescreen's voicemail shortcut.

Thanks!

I also need to know how to switch from the orange home screen to the standard windows one, or toshiba's... I can't find the settings anywhere!
Phone: Dell Streak Running: Gingerbread
Phone: HTC Dream (G1) Running: Gingerbread
Tablet: HTC Flyer Running: Honeycomb

Goodbye WinMo, you will not be missed!