lost all viewing programs!

Hiya! i tried to run a gspot program and it failed. now, i cant view NO files on WMV or quicktime, says “Class Not Registered” and QT says " cant find correct codec” and when i logged on to this site, i got an error saying macromedia flash’s certificate has expired.. the error gspot said to look for was “unknown audio #15” said to install or uninstall it.. i dont know where that is.. any ideas to get back up and running???

thanks
Zinc...