dual boot - Error:No Such Device ... Grub Rescue>_

I am a totally new Ubuntu user.

I had Windows 7 and Ubuntu 14.04LTS side by side.I have 2 HDD- one 160 GB and 1TB.

• I decided to delete ubuntu and change to ubuntu 12.04 as 14.04 does not have much softwares..


• I opened Disk Management and deleted two partitions which were unnamed(so they belonged to Ubuntu).(Three of the local disks changed to dynamic)


• I forgot to proceed to the further steps which said to fix MBR(I got no idea what it is).



• I restarted the machine and I got this:

  
  
  
  

  error:no such device .........

  
  
  

  Entering rescue mode...

  
  
  

  grub rescue>_




• I tried to use Boot Repair and upgrade grub,but Boot Repair is giving an error and grub update says there is not enough space.

I don't know what to do.

Please help me .. Please !!