how do i re-install my 360 controller on PC? HELP

i plugged it in, thinking "microsoft".

didn't work. wanted drivers.

i went and got them. installed them. whoops, too late. the installer says
'install these before plugging it in".

gosh, thanks.

now what? i've tried EVERYTHING.

i've uninstalled the drivers, restarted, restarted in safe mode, did a
system restore to yesterday, plugged it in a different port, uninstalled
every "USB hub" type device entry in the device manager and reinstalled those
after a restart, i swore at my computer, scowled at my cat, combed the
internet, and can't find anyhting.

how to i get back to a virgin state again, so i can just install the stupid
driver and plug the stupid thing in? i remember having this problem once with
my belkin n52, and it drove me crazy. i think i've mentally blocked that
experience out of my memory.

help.