South Park

Level 7
In my experience, OSA 1.4.2 did not uninstall cleanly and in fact left behind two drivers in system32/drivers. After a lot of problems with OSA stopping unexpectedly, I manually deleted the leftovers and re-reinstalled it, now testing and hoping I can keep it.
Update: after I deleted the stray drivers and clean reinstalled it, OSA has been running OK through a Windows update and multiple reboots. I hope it keeps working, because I like the extra layer of protection at a usage of only 4 MB of RAM.