When upgrading (or fresh install) from XP to 7, get ready for the fact that your printer and scanner (if they're more than about 2 years old) and other things will probably not work with Win 7 because there is no software driver for that device included, and the printer manufacturer probably won't make one either. They like to force you to buy a new piece of hardware you don't need just because of the lack of a few lines of code that make the old devices talk to the new operating system. This is a marketing scam/plot I think Microsoft has been a deliberate partner to for a long time.
The Home version (32 bit) of Win 7 also disables the ability to network with any computer using older versions of Windows, like 2000 and maybe XP too, which still runs the most important computer in my office. (That computer isn't an internet connected toy) To get that networking ability back, you have to pay extra to upgrade again to the 64 bit version. And as usual, it's all because of a few lines of code that were strategically removed from the cheaper version just to hook people who didn't know they'd just end up paying a lot more than they intended to actually get things working again after the Win 7 upgrade. This has been standard Microsoft operating practice for decades now.