grub error no such partition on Dual boot of windows 7(32 bit) and ubuntu 12.04 64 bit on two patritions

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http://askubuntu.com – I have a HP compaq 8200 Elite CMT PC with an i7 processor and 16GB of ram. There are two hardisks on the pc one of which is 500GB and the other one is 1TB. I have a licensed copy of windows 32 bit on the 500GB which I cannot touch and I need to install a 64 bit ubuntu on the 1TB partition. The problem is when I install it normally with the grub and the ubuntu in 1TB hdd and I try to boot through it I get a grub error : no such partition. But windows does boot when I change the boot harddisk. I have tried things like boot repair,rescatux, re installing grub etc but none of them helped. I am als (HowTos)