asking a copy of windows to be transfered from one system to another is a bit too much to ask, you get
driver conflicts and other such issues.
you could try booting into safe mode and run driver sweep to uninstall all your old
drivers, but again its a long shot.
if you boot the pc with a copy of windows 7 in the drive it will run the setup installation wizard for you. But it will remove all your existing files and apps.
But it will move your old files to a windows.old folder.
oh and welcome to the forum