The 'upgrade' from Windows XP to Windows 7 isn't really that; it's a 'clean' installation that reformats your hard drive in the process. That's why Microsoft tell users this:
"To upgrade your PC from Windows XP to Windows 7, you'll need to select the Custom option during Windows 7 installation.
A custom installation doesn't preserve your programs, files, or settings".
http://windows.microsoft.com/en-GB/windows7/help/upgrading-from-windows-xp-to-windows-7#T1=tab01
So the chances of your old files and folders still existing are almost zero. Forensic science technicians (such as those employed by the police and security services) can sometimes recover files from a reformatted drive but I suspect that, after a year of your computer writing new files to the drive, even they would regard it as a hopeless task.
However if anything can find your files it will probably be Recuva. It's a freebie, so it might be worth giving it a go:
https://www.piriform.com/recuva/download/standard