Getting a Black Login Screen at ubuntu boot-up ??

Hey.Dont be desperate!!
I too had the same problem some time ago.I had installed  ubuntu 10.04  inside Window xp(wubi).I was using it from 2 months and everything was working well since last night.When i boot up my system next morning ,i got a black login screen .I tried a lot to get my Gnome-Gui as it was before but i couldn't get  so started to curse ubuntu . I had very important stuff in home folder and web root directory that i needed at any cost.So finally i decided  to re-install it but still i hadn't  want to  lost my data.So I did following to get my data back(Home folder,web root Directory,Desktop) so then i re-installed the ubuntu.
                                                                       You should have Live-cd of ubuntu to get rid of it.You should also know at which partition ubuntu is installed .Mine was at /dev/sda8.Insert Live cd and start the system.Now open the terminal and issue following commands.

1)sudo mkdir /abc
It will create a empty directory.Now issue following.
2)sudo mount /dev/sda8 /abc 
   It will mount the ubuntu's partition in directory abc.       
3)sudo mkdir /vdisk
   It will again create a new directroy

4)sudo mount -o loop /abc/ubuntu/disks/root.disk /vdisk

                                                           Done.Now you have your data of home folder,desktop and web root directory in vdisk directory.Take a back up of it.
Enjoy!!!