Hi,
I had 32 bit Windows 7 home premium provided by OEM. Recently I purchased Windows 7 professional 64 bit in order to increase my memory.(My system is 64 bit capable) I followed [1]. I am using USB for installation. I booted the system with USB. Then at disk manager I deleted all the partitions(including recovery

) Then I refreshed and click next and I got an error saying setup unable to create system partition. I also tried diskpart clean. Still no hope. So I am stuck with a formated laptop. Want to get this working soon. Can anyone of you kindly enlighten me on this issue.
[1]http://www.sevenforums.com/tutorials/1649-clean-install-windows-7-a.html