Here's the most direct way to get rid of it.
Fresh from a reboot, kill all processes related to Rundll32.exe.
Delete the friggin file. It's usually in the temp directory somewhere.
If the adware/spyware doesn't have any other hold in your system, this should work. It's a known variant of the Startpage family. You get it from lots of sources, like unscrupulous freeware sites (usually the ad supported ones). Yeah, and underground (read: illegal) sources.