Fastest way to switch from Win 7 32-bit to 64-bit?

There is only one way, fresh install.

Only real reason is to get access to 4GB+ of ram. Otherwise its more or less the same.

Don't bother upgrading to 64 bit unless you have MORE than 4GB of memory. If you have 6GB or 8GB 64bit is a must. However, if your rig what I see in your signature, stick to 32bit, your performance will actually be better.

Since you aren't using over 4gb there is really not much benefit (other than 0.3-0.5gb of extra ram)

But I think windows 7 (and maybe previous versions) copy all your files and puts them into a windows.old folder type thing so you can just copy paste the files( you can't transfer programs this way, just installers, pictures, docs, etc)

not true. as was said a clean install is required

the easy way would be to find another 80g sata drive. unplug your two other drives and install windows 64 on the new drive.
then plug the old drives back in and just change the first boot device when you need to boot into windows 64.

1) A clean install is required. Period..
2) Use windows easy transfer to export all of your settings and files.
3) After a clean install of windows 64 bit, you can then import all or parts of your files and settings.
4) Only a reinstall of your apps will be required.

why does anyone need today to reinstall windows if you put it on a clean new drive and boot from it???
all you need to do is in the bios is change your boot order if you want to boot from windows 32 or windows 64 hard drive.
if he had a larger hard drive he could have used windows own boot manager and had a two boot os on the same hard drive.

all great answers... so since i only have 4Gb of Ram 64-bit doesn't matter?

Also 1 question hasn't been answered.. by apps do u mean programs?   this isnt a phone lol... like will i need to reinstall a game downloaded from the internet... or can i transfer that file over aswell? like Crossfire, World Of Warcraft, COD..etc...

Yes, I mean programs. The installation of programs involves registry entries which can't be transferred.

Windows easy transfer will transfer all your download files. It would not be hard to reinstall your games from those files, assuming you still have them.

Going from a 32 bit Windows installation to a 64 bit installation request a fresh install. The file system itself doesn't change so if you want to keep all of your existing programs you can offload them to a storage device or another hard drive.

There are many many architectural changes present in the 64 bit extensions which clean up a lot of the crap that Intel left in the legacy operating mode (32 bit). Contrary to popular belief, 32 bit operating systems can address more than 4GB of memory and Windows has been able to do this since Windows 2000. Consumer versions of Windows are limited to 4GB for marketing purposes. Applications can also use more than 4GB if they are PAE aware (many are not) and are run on an operating system that is not capped. 64 bit addressing is required to use the NX bit which is a very useful security measure.

64 bit extensions also increase the number of general purpose registers from 8 to 16, the number of XMM registers (registers used for special SSE and MMX functions) is also doubled from 8 to 16

The width of general purpose registers is increased from 32 bits to 64 bits. This allows long integers to be stored in a single register rather than 2, effectively quadrupling the CPUs integer capacity.

Problematic legacy features such as the original x87 floating point code have been removed from long mode. These are still available in legacy mode

Hmm, I'm certain it works that way with windows vista to windows 7, the contents of your hdd get mashed into a folder at the root directory. Not sure why they wouldn't include that option when going from 32b to 64b but I'll take your word on it.