How do I uninstall Ubuntu?
 

My buddy installed Ubuntu Linux for me and I some how forgot my Login password. I have Dual Boot with windows XP and Ubuntu and just want to erase the old Ubuntu. :confused:

Login can be restored ...
Removing Ubuntu really is not a Linux question. You boot into Windows, do the fixmbr thing (or was it fixboot?), in any case you do it in Windows. Then you go to System Management (sorry if it is wrong name) and erase the Linux partition(s). That's it.

This will help you uninstall ubuntu.

http://ubuntuforums.org/showthread.php?t=508927

Don't delete Ubuntu,it's not his fault it's yours.To change your passwd do this;
boot into recovery mode from GRUB menu and at the prompt, change the password for that user, john (assuming john is the username...)!

Code:
passwd john

or when grub starts up, you can press "e" to enter edit mode, and edit one of the lines by adding the word "single" onto the end. Then press "b" to boot into linux single mode, which will give you root privileges. From there just type
Code:
passwd username

to change your password.