I had windows 7 & Boss in my laptop. As all computers in my workplace has Ubuntu. I decided to install Ubuntu 12.04. So, I deleted the BOSS and now when I restart my laptop I get a message like this and I can't enter windows nor boot up with Ubuntu please help me restore this error. GRUB loading. Welcome to GRUB!
error: unknown file system. Entering rescue mode... grub rescue>
What should I do next?