Grub rescue - error: unknown filesystem
I am new to Linux. I had Windows 7 installed in my laptop. Yesterday I installed Ubuntu 9.0 from a free CD I got. I choose the option "Install side by side with Windows 7 loader (something like that..)". Everything went fine & I installed Ubuntu. When I restarted, I could easily boot from both Windows 7 & Ubuntu.
But later when I booted from Windows 7, I did a disk management by right clicking "my Computer" & choosing the option "Manage". Actually I deleted a drive & added that empty volume in another drive.
Now when I start my system it shows the following error:
Grub loading Unknown file system grub rescue>
I have no clue what to do now. Please help me at urgent.
Any solution in layman's language is greatly appreciated.
P.S. I want all my files on both Windows 7 & Ubuntu.