Windows XP forum: Unwanted shortcuts show up on desktop after startup

My son's XP computer - he is the only regular user and has a non-admin login account - every time he logs in following a computer restart, has some number of unwanted shortcut icons strewn around his desktop.

The number might be as few as 10 and it might be several dozen. It tends to be shortcut icons from 1-3 programs, repeated again and again. Firefox is one whose shortcut tends to come up a lot. So do shortcuts to games that haven't been played in eons. The FF shortcut is in the quick launch bar; the other shortcuts aren't.

This does not happen when I log into my (admin) account on the computer.

But I have cleaned my son's desktop so it's a recycle bin and nothing else, emptied the recycle bin, restarted - and blammo, all those unwanted shortcut icons.

The computer is AVG Free scanned nightly and nothing bad is ever discovered.

I run malwarebytes and superantispyware (updated, boot to safe mode, run program) a few times a year and this always comes clean.

Ran ccleaner on the registry and it cleaned a few things out, but this didn't fix it.

Ran msconfig, did not look super hard at the stuff in the startup tab, but nothing looked out of line.

This problem has been happening for a month or so.

What would cause a non-admin user account to repopulate its desktop with unwanted shortcut icons every time after startup, when there's no detected malware, and when the admin account on the computer doesn't do this?