Remove win 7 beta

I assume you used separate partition for each operating system? If that's the case, it should be as simple as reformatting the Win7 partition.

I believe Karmic (9.10) ships with a Disk Utility program:
System -> Administration -> "Disk Utility"

Open that utility, click on the Win7 partition, and click the delete button. The rest should be self explanatory, but if not, feel free to ask more questions.

Hi :)

Err, it does completely depend on how you have installed Ubuntu and there are many possibilities. Please help us by getting to a command-line

https://help.ubuntu.com/community/UsingTheTerminal#Starting%20a%20Terminal

and copy&paste with the mouse or type in

sudo fdisk -l

where " -l" is a lower-case " -L" and sudo will ask for your normal user password, not your SuperUser/Root one. It wont give you any stars as you type in an attempt to keep even the length of your password secret :) Please copy&paste the output from that command into here so we can have a better idea of how Ubuntu is already setup on your machine

Good luck and regards from
Tom :)