Upgraded from XP 32 bit to Windows 8 64 bit. You need to do a custom installation to achieve this. If you have some computer experience you can continue to use your existing files (but many applications will need to be reinstalled). I think it's best to install Win 8 onto a separate hard disk if you have one.
I like the new Windows. There is no Start button in the Desktop window, but think of the new 'Home' screen as one big start menu. You can find all your applications by typing a few characters into the search box, and they open up either in full-page mode, or inside the Desktop window.
Windows 8 has its own anti-virus and firewall, so no need to get a separate program to slow it down.
Review update - things I forgot to mention 1st time round:
* You are confronted with your 1st tough decision upon installing... should you set up a Microsoft account or a Local account?? Here's my advice: Set your *1st* account up as a *Local* account, it is the admin account. You won't have access to any apps in the App Store etc. but the admin account does *not* need these features (App Store apps are installed per-user, not for the whole computer). Once ready, you can create your user accounts for all the users you need, and these are suitable as Microsoft accounts - all the new features of Win 8 will work.
* Win 8 had a built-in driver for everything on my computer - it's 6 years old, so not surprising. Old logitech webcam does not work, nor does bluetooth modem.
* I can dual boot with XP after custom-installing on a separate drive - I do not enjoy going back to XP, but it's there if I need it.
* I am resisting re-installing iTunes, it pretty much destroyed my XP performance, and I don't want to risk ruining Win 8 - which is smooth and fast enough, even on my old computer.
* If you previously used Windows Live Mail: You can install it again in Win 8, and point the mail store to your old location. It upgrades beautifully, and all you will need to do is put your passwords in again. All your messages, accounts etc will be set up. You need to export your contacts from the old installation and import them into the new version. Search the web for detailed instructions on locating and setting the mail store for Windows Live Mail. It needs .Net 3.5 and I could only install that from the Win 8 DVD, it did not work from the web - again, search the web for installing .Net 3.5 in Win 8.
2nd update: Also worth mentioning Windows 8 has built-in parental controls, using Microsoft logins. For your children's login accounts, you can get detailed activity reports, and the ability to block various web sites and applications if you need to.