I would just make an administrative account and uninstall.
You can also use the built in adminstrator. Built-in Administrator Account - Enable or Disable
To make sure that this does not happen again, make sure that UAC is turned on. User Account Control - UAC - Change Notification Settings
You might, also, want to download and use Win Patrol. It will notify you of any changes that are being made. http://www.winpatrol.com/
The software is so good, that I have the paid version, but the free will suit you just fine.