It may help to take a step back for a bit and ask exactly what you're trying to achieve by converting it from one format to the other? You may be approaching something the wrong way
It is important, you download 32-bit Windows 7 Beta even if you're running on 64-bit hardware since Virtual PC 2007 only supports 32-bit guest operating systems. If you want to try the 64-bit edition in a virtualized environment, then use Hyper-V.
thanks all... I have achieved what I was trying to do..
I was trying to load up either .iso to virtual pc or convert .iso to .vhd to load it up on Virtual PC 2007 and I have managed to load .iso in virtual pc...
Yes, I tried 64 BIT Windows 7 RC but it didn't work so I tried 32 BIT and it worked fine... but it's running slow on virtual pc even though I have given 2 GB virtual RAM to it...!