Problems with Event Viewer,Task Schedular,Defragger not starting

[stinman]

It all started when Media Center would not stop recording a show,it still says it is recording 2 days later.I went to check Event viewer and it would not start,said the check if it was running.I tried to re-start in Services and got error1747;could not start,the authentication service is unknown. I clicked on Task Scheduler and it would not start either error 1068: The dependency service or group failed to start on local computer.I tried to find everything that was a dependent on each other,RPC and others but all was running.So something is corrupted,any ideas anyone?

stinman

Gateway GM5664,Vista Home Premium 9600 Phenom Quad

Core Processors 2.3ghz, 1tb HDD space

GGC-H20N BDDVDRW Multi drive,HD 2400xt

Video Card,PDVD Ultra 8 & 7.3,LG 22' Flatron monitor

47' LG 1080p LCD