Upgrading from vista 32 bit to windows 7 64 bit?

After booting to the install disk, follow the directions for "Custom install with format" or the 32bit to 64 bit upgrade instructions here: http://windows.microsoft.com/en-US/windows7/Installing-and-reinstalling-Windows-7

Okay so I am going to upgrade to windows 7 64 bit, I so far have made it through the upgrade assistant. Now when I put in the actual installation disk, in essence it tells me that this disk isn't compatible with my form of windows, blah blah blah blah. But then it says "to install a new copy of windows, restart (boot) your computer using the installation disc, and then select Custom (advanced). My question is how to I boot my computer using the installation disk?

With the DVD in, restart.  When the F2 and F12 options appear in the top-right corner, press F12 and select CD/DVD drive to boot to.  You can't upgrade directly between architectures (x64/x86) on ANY OS, so it must be a clean install (from scratch) ... the "upgrade" option should be grayed out, which is why it tells you to choose the other option (Custom/Advanced).