going out of support soon) to Windows 8.1 64-bit because.. well, it's cheaper to go the Windows 8.x route than Windows 7 and 8 does have some interesting features.
You can't really upgrade Windows XP to Windows 8.1 in the traditional sense, it is basically a completely new installation but it does retain your original Windows XP data so you can get to it later. But there's a gotcha here.
Windows 8.1 is a free upgrade to Windows 8, and I already had a Windows 8 upgrade disk that I bought a few months back. Upgrading from Windows XP to Windows 8 does create a set of backup files in a folder called windows.old so you can recover your data, including what was in the C:\Documents and Settings folder. So, in theory you just copy the old data from that folder into your new Documents folder.
Here's the gotcha. If you're like me, you've probably been putting off the Windows 8 upgrade until you can have Windows 8.1 which brings back the Start button. So the obvious next step is to do that (although you need to install KB2871389 to show Windows 8.1 in the app store). You can then do the 3GB+ download to install Windows 8.1 over Windows 8 which runs pretty smoothly. But before you do that.. remember to take your data out of the windows.old folder!
The trap here is that when you upgrade from Windows 8 to Windows 8.1, the contents of the windows.old folder are deleted and overwritten again, destroying the backup data from Windows XP.
Uh-oh. It's a good job that I'm paranoid about backups, so nothing was lost. But it's easy to see that people could lose data if they don't recover it from windows.old before they did the Windows 8.1 upgrade.
It really, really is worth investing in some offline storage or other backup medium before you do this. I took the opportunity to clone Windows XP to a new SSD drive before doing the upgrade and I disconnected the original hard disk, and I also made an offline backup to be on the safe side. But if I had just ploughed on and done the deed then I would have lost irreplaceable data.
Windows 8.1 is.. well, weird. But it does run very quickly on my four-year-old Dell Precision workstation with the SSD drive and a memory upgrade. Apart from the vanishing data it all went remarkably smoothly (if you are knowledgeable about Windows systems) and it didn't require any unpleasantness such as driver disks. The application troubleshooting is pretty awesome for apps that don't run properly under the new OS, and there are only a few really ancient 16-bit apps that I can't get to work that need recoding. Ah well, it should keep the computer up-to-date with security updates until 2023 which should easily be longer than the expected lifespan of the machine..