i installed flash player from the adobe site. along with it came google toolbar, pcbooster and knight.
You DIDN'T install it from here.
Adobe DOES NOT HAVE and HAS NEVER HAD anything to do with PCBooster or Knight. And you always have the option to "opt out" of downloading and installing Google Chrome & Google Toolbar or McAfee Security Scan (whichever is offered).
You were tricked by a fake site, into downloading malware.
There's a lot of this going on right now.
Unfortunately, It's a long and drawn out legal battle for Adobe to track down and shut down these fake sites, and they pop back up just as fast.
You'll most likely need to take it into a local shop to get it restored.