Windows Vista - Selecting 64-bit version for Wndows Vista while instalation

Hi,


Can anyone help me selecting 64bit version of windows Vista while installing.

I usually did n the currently installed version is for 32-bit(windows vista).

Microsoft gives both the 64bit and 32bit versions for free as long as you have one of the keys. The keys for 64bit and 32bit are different. To request a 64bit cd to be sent to you, you need to fill this out:
http://www.microsoft.com/windowsvista/1033/ordermedia/default.mspx

It's free but shipping is I think about $10. They will send you a DVD with 64bit Vista on it. You'll install it but I've heard you need to call them to get yourself a key because like I said the 32bit and 64bit keys are different. Thy person over the phone will ask for your 32bit key and they'll give you a new key for the 64bit.
Note :if you only have a 32-bit processor then you can't install 64-bit  version

Thanks All,

I've installed 32-bit Vista on the primary partition whose size is 20GB, and another 4 partitions of 50GB.


1) Will all my softwares that i already installed on 32-bit Vista work after upgrading it to 64 bit? If yes How can i get   backup as well as restoring done?
2) is 20 GB sufficient for Vista 64 bit? If no how can i increase its size?