Upgrade: Win 7 32-bit to 64 bit or Vista 64 bit to win 7 64

I'm helping a friend. I am computer literate (more or less) but not computer savvy. She has 2 computers to choose from to improve. An Acer running 64 bit Vista that has her files on it, and a Dell w/AMD X2 processor running Win 7 Prof 32 bit (AMD says this processor can run 64 bit applications). Both computers have 4 GB RAM. Which would be easier to upgrade to Win 7 64 bit. She has very few applications, mostly just document and photo files. I've read about clean upgrades, but Windows 7 "upgrade" seems to have a custome installation process that would be easier (save files, run disk, reload applications and files). Is this similar to creating a clean install?

With 4gb RAM I'd stick with 32 bit Win7 and do the Clean Reinstall linked above, following the steps to get and keep a perfect install.

If you want to do an in-place upgrade , you can do that using win 7 64 bit dvd and run it on your Vista x64 system.

Upgrading from Windows Vista to Windows 7 - Help & How-to - Microsoft Windows

( 4gb ram is plenty for x64. I am using 2gb ram and it works great with Vista x64 and win7 x64 )


There can sometimes be issues with in place upgrades - so just in case - make an image of the Vista system first

Use any free imaging program - macrium is popular. Macrium Reflect FREE Edition - Information and download

Thanks to both. For clarity, the "clean install" can be accomplished by choosing Custom in the Win 7 64 bit installation disk, right? Then I reinstall the files that I previously saved via Easy Transfer (direct cable or memory device)?
Thanks

Please read and follow the steps in Clean Reinstall - Factory OEM Windows 7. It lays out the best scheme for backups and what works best to get and keep a perfect install.

Thanks to all!