Clean install -> start setup -> cannot login any longer ???

[Thomas Blasejewicz]

Situation:
Did (again) a clean install of 10.04 using the entire disk for it.
Ran update: 102 MB -> reboot
Installed Ubuntu Tweak
Setup: Thunderbird / Firefox = working with wired network

Since this was an issue before, I disabled "KMS" following the
instructions someone gave me in private:
$ gksu gedit /etc/default/grub
change the line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash radeon.modeset=0"

save the file. Now:
$ sudo update-grub

That will add the setting to your grub file as well. Reboot.
>> >> https://wiki.ubuntu.com/X/KernelModeSetting

Working so far.
Next: according to some other instructions I copies some "driver files"
that are supposed to be required to make my wireless network function ->

Make a folder called "wireless" that contains
"b43" and "b43legacy".
sudo cp -r ~/wireless/* /lib/firmware/
then press enter.
You'll be asked for your password to authorise the copy.
If it doesn't give any errors then all was successful. You can delete
the "wireless" folder, and reboot your computer to make the driver active.

Problem starts here:
"b43" and "b43legacy" appeared under /lib/firmware/
BUT had a white cross in the lower right corner of their respective icons.

Rebooted

Now I get a screen looking completely different from what I just have set up
AND I am asked for my name and password.
BUT my password is NOT accepted.
Neither under my name nor under "other"
So, I cannot even get into the system any more.

What is this all about?????
Is there a way around it??
Or do I have to do the whole (please choose your own profanity here)
thing again???