This question appeared between two computer technicians that are friends of mine.
One was saying that the user profile's size (mainly regarding desktop content) would affect boot time and even general performance.
The other said that it was irrelevant. User profile size and desktop content does not affect boot time or performance.
The specific problem was discussed when one of their clients was having boot time issues.
The 1st technician said that moving the desktop content to an "internal" folder, having only the folder shortcut on the desktop would solve the issue. It did work (boot time became acceptable), so he believes he is correct.
The 2nd technician says that moving the desktop content broke any links to files that might be slowing the system, therefore he didn't correct the real problem, but only solved the issue with the wrong solution.
So the question is: Does user profile size and desktop content affect boot time in Windows 7?
Edit: Clarification from the comments follows.
The boot time:
The boot time we considered stands between pressing the power button and the load of the google logo on IE. IE is opened by pressing the shortcut on the taskbar as soon as it loads.
The desktop and user profile:
"Desktop content" regards files stored on the desktop. "User profile size" is determined by the control panel's options to view the user profile's size.