The "Downloads" folder is a bloat trap for random files. Treat it like a temp directory and clean it every startup.

cleantemp.cmd

:: This is free and unencumbered software released into the public domain
:: using the Unlicense. Please refer to <http://unlicense.org/>

:: This script will completely delete and then recreate your "Downloads" and "Temp" folders in your home directory.
:: This should work for pretty much any NT based version of Windows. If you are still on Windows 9x for some reason, I am sorry.

:: Place this file in "%HOMEDRIVE%%HOMEPATH%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\cleantemp.cmd"
:: or similar to have it run automatically at startup.

:: If, like me, you like to have an explicit Temp directory in your home folder. If not, delete or comment this out.
rd /s /q %HOMEDRIVE%%HOMEPATH%\Temp
md %HOMEDRIVE%%HOMEPATH%\Temp

:: On some versions of Windows, this may delete your download folder's automatic special icon.
:: It is left as an exercise for the user to figure out how to deal with this.
rd /s /q %HOMEDRIVE%%HOMEPATH%\Downloads
md %HOMEDRIVE%%HOMEPATH%\Downloads

crontab.freebsd

# This is free and unencumbered software released into the public domain
# using the Unlicense. Please refer to <http://unlicense.org/>

# Works on FreeBSD. May work on other Unix work-alikes. YMMV depending on your cron scheduler software.

SHELL=/bin/sh
# HOME=/home/<your username>
PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin
LC_ALL="en_US.UTF-8"
LANG="en_US.UTF-8"
CHARSET="UTF-8"

# Order of crontab fields
# minute	hour	mday	month	wday	command


# This assumes your cron scheduler supports special timing shortcuts like @reboot
@reboot						cd ${HOME}/tmp/ && find . -delete
@reboot						cd ${HOME}/Downloads/ && find . -delete