Halo update error PLEASE HELP!!

[L3G470]

For some reason i had to uninstall and reinstall halo and when i start the update it goes all the way to the 100% and then i get an error screen saying that chktrust.exe didn't intize properly and there is nothing i can do the error code that come up with is is 0xc0000142 and i've searched on google and i couldn't find anything that helped. If it helps i also get the same error while trying to start cmd.exe. If anyone has had this problem or somthing like it and fixed i would be externaly greatful, if you could tell me how you fixed it or if you have any suggestions or possible reasons its doing this. If it helps here is a pic showing the error.