Get that off there immediately! It's BAD.
"Metacafe is a kind of malicious programs that is setup on computers and
seeks information about users without their attaintment. Metacafe is
known to transfigure PC settings resulting in sluggish connection
speeds, diverse home web pages and waste of global Internet or lock down
of other softwares creating a requirement to remove threat with special removal tool."
It is here: http://www.securitystronghold.com/gates/link/0/2/?url=_d1_MetacafeRemovalTool.exe
The program protects your computer against this Metacafe virus that
harms your computer and breaks your privacy. It can scan your hard disks
and registry and destroy any manifestation of Metacafe.
If it's been on there too long, it may of screwed up important files. You can then try going to command prompt (just use run on the start menu (type cmd in the run box), or going to start menu, then All programs then accessories and choose command prompt) and type sfc /scannow. That should repair any damaged system files. If that doesn't work, you can try a repair disk if you have an original operating system CD, if all else fails get your important stuff off there and reinstall. Hopefully it hasn't done any damage, but get metacafe off there asap!