Reinstalling Ubuntu.

[Rick]

Hi list.
I am dual booting Ubuntu 7.04 with windows XP.
I had sighted help to install Ubuntu before I figured out how to get a 
talking install.
I think the person that helped me failed to read everything on the screen, 
because I cant access the internet, or my cd drive, or any storage media.
I cant do anything as administrator because when it asks for my password it 
says invalid password.
It even asks for the password when I am logged in as administrator.
I cant even seem to find the root folder.
I used the talking installer to try to replace Ubuntu 7.04 with 7.10.
I get as far as the screen where it asks you if you want to erase  the disk, 
I choose the one that says something like resize partition and set the 
slider to 100 percent.
Then I hit forward and that's where it hangs.
It says something like scanning disk, and then nothing.
No speech or anything.
I left it run over night, in the morning still nothing.
I had to hit the off button on the tower and restart the computer to get the 
CD out.
I tried this several times.
Any ideas on what I'm doing wrong, or could somebody please point me to some 
documentation on reinstalling with a dual boot system?
Thanks in advance.