Using Seagate Disk Management which is basically Acronis True Image I cloned my old hard drive (80GB capacity with a C: and D: partition) to a new 250GB drive but despite following all the instructions I couldn't resize the C: boot partition. Even trying automatic as well as manual had no effect. In the end, after a lot of messing about, I cloned the drive and resized the D: partition to the required size and moved it to the end of the disk leaving an unused part between them. I then used Diskpart extend command under DOS to extend the primary partition to fill up the gap hence giving me the effect I wanted. However this seems a very convoluted way of doing it.